Switch over to Lerna + Yarn Workspaces setup for a mono-repo approach

6 files changed, 0 insertions, 1600 deletions

diff --git a/src/contract_wrappers/contract_wrapper.ts b/src/contract_wrappers/contract_wrapper.ts
deleted file mode 100644
index 7997b1647..000000000
--- a/src/contract_wrappers/contract_wrapper.ts
+++ /dev/null
@@ -1,152 +0,0 @@
-import * as _ from 'lodash';
-import * as Web3 from 'web3';
-import {BlockAndLogStreamer, Block} from 'ethereumjs-blockstream';
-import {Web3Wrapper} from '../web3_wrapper';
-import {AbiDecoder} from '../utils/abi_decoder';
-import {
-    ZeroExError,
-    InternalZeroExError,
-    Artifact,
-    LogWithDecodedArgs,
-    RawLog,
-    ContractEvents,
-    SubscriptionOpts,
-    IndexedFilterValues,
-    EventCallback,
-    BlockParamLiteral,
-    ContractEventArgs,
-} from '../types';
-import {constants} from '../utils/constants';
-import {intervalUtils} from '../utils/interval_utils';
-import {filterUtils} from '../utils/filter_utils';
-
-export class ContractWrapper {
-    protected _web3Wrapper: Web3Wrapper;
-    private _abiDecoder?: AbiDecoder;
-    private _blockAndLogStreamer: BlockAndLogStreamer|undefined;
-    private _blockAndLogStreamInterval: NodeJS.Timer;
-    private _filters: {[filterToken: string]: Web3.FilterObject};
-    private _filterCallbacks: {[filterToken: string]: EventCallback<ContractEventArgs>};
-    private _onLogAddedSubscriptionToken: string|undefined;
-    private _onLogRemovedSubscriptionToken: string|undefined;
-    constructor(web3Wrapper: Web3Wrapper, abiDecoder?: AbiDecoder) {
-        this._web3Wrapper = web3Wrapper;
-        this._abiDecoder = abiDecoder;
-        this._filters = {};
-        this._filterCallbacks = {};
-        this._blockAndLogStreamer = undefined;
-        this._onLogAddedSubscriptionToken = undefined;
-        this._onLogRemovedSubscriptionToken = undefined;
-    }
-    /**
-     * Cancels all existing subscriptions
-     */
-    public unsubscribeAll(): void {
-        const filterTokens = _.keys(this._filterCallbacks);
-        _.each(filterTokens, filterToken => {
-            this._unsubscribe(filterToken);
-        });
-    }
-    protected _unsubscribe(filterToken: string, err?: Error): void {
-        if (_.isUndefined(this._filters[filterToken])) {
-            throw new Error(ZeroExError.SubscriptionNotFound);
-        }
-        if (!_.isUndefined(err)) {
-            const callback = this._filterCallbacks[filterToken];
-            callback(err, undefined);
-        }
-        delete this._filters[filterToken];
-        delete this._filterCallbacks[filterToken];
-        if (_.isEmpty(this._filters)) {
-            this._stopBlockAndLogStream();
-        }
-    }
-    protected _subscribe<ArgsType extends ContractEventArgs>(
-        address: string, eventName: ContractEvents, indexFilterValues: IndexedFilterValues, abi: Web3.ContractAbi,
-        callback: EventCallback<ArgsType>): string {
-        const filter = filterUtils.getFilter(address, eventName, indexFilterValues, abi);
-        if (_.isUndefined(this._blockAndLogStreamer)) {
-            this._startBlockAndLogStream();
-        }
-        const filterToken = filterUtils.generateUUID();
-        this._filters[filterToken] = filter;
-        this._filterCallbacks[filterToken] = callback;
-        return filterToken;
-    }
-    protected async _getLogsAsync<ArgsType extends ContractEventArgs>(
-        address: string, eventName: ContractEvents, subscriptionOpts: SubscriptionOpts,
-        indexFilterValues: IndexedFilterValues, abi: Web3.ContractAbi): Promise<Array<LogWithDecodedArgs<ArgsType>>> {
-        const filter = filterUtils.getFilter(address, eventName, indexFilterValues, abi, subscriptionOpts);
-        const logs = await this._web3Wrapper.getLogsAsync(filter);
-        const logsWithDecodedArguments = _.map(logs, this._tryToDecodeLogOrNoop.bind(this));
-        return logsWithDecodedArguments;
-    }
-    protected _tryToDecodeLogOrNoop<ArgsType extends ContractEventArgs>(
-        log: Web3.LogEntry): LogWithDecodedArgs<ArgsType>|RawLog {
-        if (_.isUndefined(this._abiDecoder)) {
-            throw new Error(InternalZeroExError.NoAbiDecoder);
-        }
-        const logWithDecodedArgs = this._abiDecoder.tryToDecodeLogOrNoop(log);
-        return logWithDecodedArgs;
-    }
-    protected async _instantiateContractIfExistsAsync<ContractType extends Web3.ContractInstance>(
-        artifact: Artifact, addressIfExists?: string): Promise<ContractType> {
-        const contractInstance =
-            await this._web3Wrapper.getContractInstanceFromArtifactAsync<ContractType>(artifact, addressIfExists);
-        return contractInstance;
-    }
-    private _onLogStateChanged<ArgsType extends ContractEventArgs>(removed: boolean, log: Web3.LogEntry): void {
-        _.forEach(this._filters, (filter: Web3.FilterObject, filterToken: string) => {
-            if (filterUtils.matchesFilter(log, filter)) {
-                const decodedLog = this._tryToDecodeLogOrNoop(log) as LogWithDecodedArgs<ArgsType>;
-                const logEvent = {
-                    ...decodedLog,
-                    removed,
-                };
-                this._filterCallbacks[filterToken](null, logEvent);
-            }
-        });
-    }
-    private _startBlockAndLogStream(): void {
-        this._blockAndLogStreamer = new BlockAndLogStreamer(
-            this._web3Wrapper.getBlockAsync.bind(this._web3Wrapper),
-            this._web3Wrapper.getLogsAsync.bind(this._web3Wrapper),
-        );
-        const catchAllLogFilter = {};
-        this._blockAndLogStreamer.addLogFilter(catchAllLogFilter);
-        this._blockAndLogStreamInterval = intervalUtils.setAsyncExcludingInterval(
-            this._reconcileBlockAsync.bind(this), constants.DEFAULT_BLOCK_POLLING_INTERVAL,
-        );
-        let removed = false;
-        this._onLogAddedSubscriptionToken = this._blockAndLogStreamer.subscribeToOnLogAdded(
-            this._onLogStateChanged.bind(this, removed),
-        );
-        removed = true;
-        this._onLogRemovedSubscriptionToken = this._blockAndLogStreamer.subscribeToOnLogRemoved(
-            this._onLogStateChanged.bind(this, removed),
-        );
-    }
-    private _stopBlockAndLogStream(): void {
-        (this._blockAndLogStreamer as BlockAndLogStreamer).unsubscribeFromOnLogAdded(
-            this._onLogAddedSubscriptionToken as string);
-        (this._blockAndLogStreamer as BlockAndLogStreamer).unsubscribeFromOnLogRemoved(
-            this._onLogRemovedSubscriptionToken as string);
-        intervalUtils.clearAsyncExcludingInterval(this._blockAndLogStreamInterval);
-        delete this._blockAndLogStreamer;
-    }
-    private async _reconcileBlockAsync(): Promise<void> {
-        try {
-            const latestBlock = await this._web3Wrapper.getBlockAsync(BlockParamLiteral.Latest);
-            // We need to coerce to Block type cause Web3.Block includes types for mempool blocks
-            if (!_.isUndefined(this._blockAndLogStreamer)) {
-                // If we clear the interval while fetching the block - this._blockAndLogStreamer will be undefined
-                this._blockAndLogStreamer.reconcileNewBlock(latestBlock as any as Block);
-            }
-        } catch (err) {
-            const filterTokens = _.keys(this._filterCallbacks);
-            _.each(filterTokens, filterToken => {
-                this._unsubscribe(filterToken, err);
-            });
-        }
-    }
-}
diff --git a/src/contract_wrappers/ether_token_wrapper.ts b/src/contract_wrappers/ether_token_wrapper.ts
deleted file mode 100644
index 3cd2f0224..000000000
--- a/src/contract_wrappers/ether_token_wrapper.ts
+++ /dev/null
@@ -1,87 +0,0 @@
-import * as _ from 'lodash';
-import BigNumber from 'bignumber.js';
-import {Web3Wrapper} from '../web3_wrapper';
-import {ContractWrapper} from './contract_wrapper';
-import {TokenWrapper} from './token_wrapper';
-import {EtherTokenContract, ZeroExError} from '../types';
-import {assert} from '../utils/assert';
-import {artifacts} from '../artifacts';
-
-/**
- * This class includes all the functionality related to interacting with a wrapped Ether ERC20 token contract.
- * The caller can convert ETH into the equivalent number of wrapped ETH ERC20 tokens and back.
- */
-export class EtherTokenWrapper extends ContractWrapper {
-    private _etherTokenContractIfExists?: EtherTokenContract;
-    private _tokenWrapper: TokenWrapper;
-    private _contractAddressIfExists?: string;
-    constructor(web3Wrapper: Web3Wrapper, tokenWrapper: TokenWrapper, contractAddressIfExists?: string) {
-        super(web3Wrapper);
-        this._tokenWrapper = tokenWrapper;
-        this._contractAddressIfExists = contractAddressIfExists;
-    }
-    /**
-     * Deposit ETH into the Wrapped ETH smart contract and issues the equivalent number of wrapped ETH tokens
-     * to the depositor address. These wrapped ETH tokens can be used in 0x trades and are redeemable for 1-to-1
-     * for ETH.
-     * @param   amountInWei      Amount of ETH in Wei the caller wishes to deposit.
-     * @param   depositor   The hex encoded user Ethereum address that would like to make the deposit.
-     * @return Transaction hash.
-     */
-    public async depositAsync(amountInWei: BigNumber, depositor: string): Promise<string> {
-        assert.isValidBaseUnitAmount('amountInWei', amountInWei);
-        await assert.isSenderAddressAsync('depositor', depositor, this._web3Wrapper);
-
-        const ethBalanceInWei = await this._web3Wrapper.getBalanceInWeiAsync(depositor);
-        assert.assert(ethBalanceInWei.gte(amountInWei), ZeroExError.InsufficientEthBalanceForDeposit);
-
-        const wethContract = await this._getEtherTokenContractAsync();
-        const txHash = await wethContract.deposit.sendTransactionAsync({
-            from: depositor,
-            value: amountInWei,
-        });
-        return txHash;
-    }
-    /**
-     * Withdraw ETH to the withdrawer's address from the wrapped ETH smart contract in exchange for the
-     * equivalent number of wrapped ETH tokens.
-     * @param   amountInWei  Amount of ETH in Wei the caller wishes to withdraw.
-     * @param   withdrawer   The hex encoded user Ethereum address that would like to make the withdrawl.
-     * @return Transaction hash.
-     */
-    public async withdrawAsync(amountInWei: BigNumber, withdrawer: string): Promise<string> {
-        assert.isValidBaseUnitAmount('amountInWei', amountInWei);
-        await assert.isSenderAddressAsync('withdrawer', withdrawer, this._web3Wrapper);
-
-        const wethContractAddress = await this.getContractAddressAsync();
-        const WETHBalanceInBaseUnits = await this._tokenWrapper.getBalanceAsync(wethContractAddress, withdrawer);
-        assert.assert(WETHBalanceInBaseUnits.gte(amountInWei), ZeroExError.InsufficientWEthBalanceForWithdrawal);
-
-        const wethContract = await this._getEtherTokenContractAsync();
-        const txHash = await wethContract.withdraw.sendTransactionAsync(amountInWei, {
-            from: withdrawer,
-        });
-        return txHash;
-    }
-    /**
-     * Retrieves the Wrapped Ether token contract address
-     * @return  The Wrapped Ether token contract address
-     */
-    public async getContractAddressAsync(): Promise<string> {
-        const wethContract = await this._getEtherTokenContractAsync();
-        return wethContract.address;
-    }
-    private _invalidateContractInstance(): void {
-        delete this._etherTokenContractIfExists;
-    }
-    private async _getEtherTokenContractAsync(): Promise<EtherTokenContract> {
-        if (!_.isUndefined(this._etherTokenContractIfExists)) {
-            return this._etherTokenContractIfExists;
-        }
-        const contractInstance = await this._instantiateContractIfExistsAsync<EtherTokenContract>(
-            artifacts.EtherTokenArtifact, this._contractAddressIfExists,
-        );
-        this._etherTokenContractIfExists = contractInstance as EtherTokenContract;
-        return this._etherTokenContractIfExists;
-    }
-}
diff --git a/src/contract_wrappers/exchange_wrapper.ts b/src/contract_wrappers/exchange_wrapper.ts
deleted file mode 100644
index fe0c5bc00..000000000
--- a/src/contract_wrappers/exchange_wrapper.ts
+++ /dev/null
@@ -1,866 +0,0 @@
-import * as _ from 'lodash';
-import * as Web3 from 'web3';
-import BigNumber from 'bignumber.js';
-import {schemas} from '0x-json-schemas';
-import {Web3Wrapper} from '../web3_wrapper';
-import {
-    ECSignature,
-    ExchangeContract,
-    ExchangeContractErrCodes,
-    ExchangeContractErrs,
-    ZeroExError,
-    OrderValues,
-    OrderAddresses,
-    Order,
-    SignedOrder,
-    ExchangeEvents,
-    SubscriptionOpts,
-    IndexedFilterValues,
-    OrderCancellationRequest,
-    OrderFillRequest,
-    LogErrorContractEventArgs,
-    LogFillContractEventArgs,
-    LogCancelContractEventArgs,
-    LogWithDecodedArgs,
-    MethodOpts,
-    ValidateOrderFillableOpts,
-    OrderTransactionOpts,
-    RawLog,
-    EventCallback,
-    ExchangeContractEventArgs,
-    DecodedLogArgs,
-} from '../types';
-import {assert} from '../utils/assert';
-import {utils} from '../utils/utils';
-import {OrderValidationUtils} from '../utils/order_validation_utils';
-import {ContractWrapper} from './contract_wrapper';
-import {TokenWrapper} from './token_wrapper';
-import {decorators} from '../utils/decorators';
-import {AbiDecoder} from '../utils/abi_decoder';
-import {ExchangeTransferSimulator} from '../utils/exchange_transfer_simulator';
-import {artifacts} from '../artifacts';
-
-const SHOULD_VALIDATE_BY_DEFAULT = true;
-
-/**
- * This class includes all the functionality related to calling methods and subscribing to
- * events of the 0x Exchange smart contract.
- */
-export class ExchangeWrapper extends ContractWrapper {
-    private _exchangeContractIfExists?: ExchangeContract;
-    private _orderValidationUtils: OrderValidationUtils;
-    private _tokenWrapper: TokenWrapper;
-    private _exchangeContractErrCodesToMsg = {
-        [ExchangeContractErrCodes.ERROR_FILL_EXPIRED]: ExchangeContractErrs.OrderFillExpired,
-        [ExchangeContractErrCodes.ERROR_CANCEL_EXPIRED]: ExchangeContractErrs.OrderFillExpired,
-        [ExchangeContractErrCodes.ERROR_FILL_NO_VALUE]: ExchangeContractErrs.OrderRemainingFillAmountZero,
-        [ExchangeContractErrCodes.ERROR_CANCEL_NO_VALUE]: ExchangeContractErrs.OrderRemainingFillAmountZero,
-        [ExchangeContractErrCodes.ERROR_FILL_TRUNCATION]: ExchangeContractErrs.OrderFillRoundingError,
-        [ExchangeContractErrCodes.ERROR_FILL_BALANCE_ALLOWANCE]: ExchangeContractErrs.FillBalanceAllowanceError,
-    };
-    private _contractAddressIfExists?: string;
-    private static _getOrderAddressesAndValues(order: Order): [OrderAddresses, OrderValues] {
-        const orderAddresses: OrderAddresses = [
-            order.maker,
-            order.taker,
-            order.makerTokenAddress,
-            order.takerTokenAddress,
-            order.feeRecipient,
-        ];
-        const orderValues: OrderValues = [
-            order.makerTokenAmount,
-            order.takerTokenAmount,
-            order.makerFee,
-            order.takerFee,
-            order.expirationUnixTimestampSec,
-            order.salt,
-        ];
-        return [orderAddresses, orderValues];
-    }
-    constructor(web3Wrapper: Web3Wrapper, abiDecoder: AbiDecoder,
-                tokenWrapper: TokenWrapper, contractAddressIfExists?: string) {
-        super(web3Wrapper, abiDecoder);
-        this._tokenWrapper = tokenWrapper;
-        this._orderValidationUtils = new OrderValidationUtils(tokenWrapper, this);
-        this._contractAddressIfExists = contractAddressIfExists;
-    }
-    /**
-     * Returns the unavailable takerAmount of an order. Unavailable amount is defined as the total
-     * amount that has been filled or cancelled. The remaining takerAmount can be calculated by
-     * subtracting the unavailable amount from the total order takerAmount.
-     * @param   orderHash               The hex encoded orderHash for which you would like to retrieve the
-     *                                  unavailable takerAmount.
-     * @param   methodOpts              Optional arguments this method accepts.
-     * @return  The amount of the order (in taker tokens) that has either been filled or canceled.
-     */
-    public async getUnavailableTakerAmountAsync(orderHash: string,
-                                                methodOpts?: MethodOpts): Promise<BigNumber> {
-        assert.doesConformToSchema('orderHash', orderHash, schemas.orderHashSchema);
-
-        const exchangeContract = await this._getExchangeContractAsync();
-        const defaultBlock = _.isUndefined(methodOpts) ? undefined : methodOpts.defaultBlock;
-        let unavailableTakerTokenAmount = await exchangeContract.getUnavailableTakerTokenAmount.callAsync(
-            orderHash, defaultBlock,
-        );
-        // Wrap BigNumbers returned from web3 with our own (later) version of BigNumber
-        unavailableTakerTokenAmount = new BigNumber(unavailableTakerTokenAmount);
-        return unavailableTakerTokenAmount;
-    }
-    /**
-     * Retrieve the takerAmount of an order that has already been filled.
-     * @param   orderHash    The hex encoded orderHash for which you would like to retrieve the filled takerAmount.
-     * @param   methodOpts   Optional arguments this method accepts.
-     * @return  The amount of the order (in taker tokens) that has already been filled.
-     */
-    public async getFilledTakerAmountAsync(orderHash: string, methodOpts?: MethodOpts): Promise<BigNumber> {
-        assert.doesConformToSchema('orderHash', orderHash, schemas.orderHashSchema);
-
-        const exchangeContract = await this._getExchangeContractAsync();
-        const defaultBlock = _.isUndefined(methodOpts) ? undefined : methodOpts.defaultBlock;
-        let fillAmountInBaseUnits = await exchangeContract.filled.callAsync(orderHash, defaultBlock);
-        // Wrap BigNumbers returned from web3 with our own (later) version of BigNumber
-        fillAmountInBaseUnits = new BigNumber(fillAmountInBaseUnits);
-        return fillAmountInBaseUnits;
-    }
-    /**
-     * Retrieve the takerAmount of an order that has been cancelled.
-     * @param   orderHash    The hex encoded orderHash for which you would like to retrieve the
-     *                       cancelled takerAmount.
-     * @param   methodOpts   Optional arguments this method accepts.
-     * @return  The amount of the order (in taker tokens) that has been cancelled.
-     */
-    public async getCanceledTakerAmountAsync(orderHash: string, methodOpts?: MethodOpts): Promise<BigNumber> {
-        assert.doesConformToSchema('orderHash', orderHash, schemas.orderHashSchema);
-
-        const exchangeContract = await this._getExchangeContractAsync();
-        const defaultBlock = _.isUndefined(methodOpts) ? undefined : methodOpts.defaultBlock;
-        let cancelledAmountInBaseUnits = await exchangeContract.cancelled.callAsync(orderHash, defaultBlock);
-        // Wrap BigNumbers returned from web3 with our own (later) version of BigNumber
-        cancelledAmountInBaseUnits = new BigNumber(cancelledAmountInBaseUnits);
-        return cancelledAmountInBaseUnits;
-    }
-    /**
-     * Fills a signed order with an amount denominated in baseUnits of the taker token.
-     * Since the order in which transactions are included in the next block is indeterminate, race-conditions
-     * could arise where a users balance or allowance changes before the fillOrder executes. Because of this,
-     * we allow you to specify `shouldThrowOnInsufficientBalanceOrAllowance`.
-     * If false, the smart contract will not throw if the parties
-     * do not have sufficient balances/allowances, preserving gas costs. Setting it to true forgoes this check
-     * and causes the smart contract to throw (using all the gas supplied) instead.
-     * @param   signedOrder                                 An object that conforms to the SignedOrder interface.
-     * @param   fillTakerTokenAmount                        The amount of the order (in taker tokens baseUnits) that
-     *                                                      you wish to fill.
-     * @param   shouldThrowOnInsufficientBalanceOrAllowance Whether or not you wish for the contract call to throw
-     *                                                      if upon execution the tokens cannot be transferred.
-     * @param   takerAddress                                The user Ethereum address who would like to fill this order.
-     *                                                      Must be available via the supplied Web3.Provider
-     *                                                      passed to 0x.js.
-     * @param   orderTransactionOpts                        Optional arguments this method accepts.
-     * @return  Transaction hash.
-     */
-    @decorators.contractCallErrorHandler
-    public async fillOrderAsync(signedOrder: SignedOrder, fillTakerTokenAmount: BigNumber,
-                                shouldThrowOnInsufficientBalanceOrAllowance: boolean,
-                                takerAddress: string,
-                                orderTransactionOpts?: OrderTransactionOpts): Promise<string> {
-        assert.doesConformToSchema('signedOrder', signedOrder, schemas.signedOrderSchema);
-        assert.isValidBaseUnitAmount('fillTakerTokenAmount', fillTakerTokenAmount);
-        assert.isBoolean('shouldThrowOnInsufficientBalanceOrAllowance', shouldThrowOnInsufficientBalanceOrAllowance);
-        await assert.isSenderAddressAsync('takerAddress', takerAddress, this._web3Wrapper);
-
-        const exchangeInstance = await this._getExchangeContractAsync();
-        const shouldValidate = _.isUndefined(orderTransactionOpts) ?
-            SHOULD_VALIDATE_BY_DEFAULT :
-            orderTransactionOpts.shouldValidate;
-        if (shouldValidate) {
-            const zrxTokenAddress = await this.getZRXTokenAddressAsync();
-            const exchangeTradeEmulator = new ExchangeTransferSimulator(this._tokenWrapper);
-            await this._orderValidationUtils.validateFillOrderThrowIfInvalidAsync(
-                exchangeTradeEmulator, signedOrder, fillTakerTokenAmount, takerAddress, zrxTokenAddress);
-        }
-
-        const [orderAddresses, orderValues] = ExchangeWrapper._getOrderAddressesAndValues(signedOrder);
-
-        const gas = await exchangeInstance.fillOrder.estimateGasAsync(
-            orderAddresses,
-            orderValues,
-            fillTakerTokenAmount,
-            shouldThrowOnInsufficientBalanceOrAllowance,
-            signedOrder.ecSignature.v,
-            signedOrder.ecSignature.r,
-            signedOrder.ecSignature.s,
-            {
-                from: takerAddress,
-            },
-        );
-        const txHash: string = await exchangeInstance.fillOrder.sendTransactionAsync(
-            orderAddresses,
-            orderValues,
-            fillTakerTokenAmount,
-            shouldThrowOnInsufficientBalanceOrAllowance,
-            signedOrder.ecSignature.v,
-            signedOrder.ecSignature.r,
-            signedOrder.ecSignature.s,
-            {
-                from: takerAddress,
-                gas,
-            },
-        );
-        return txHash;
-    }
-    /**
-     * Sequentially and atomically fills signedOrders up to the specified takerTokenFillAmount.
-     * If the fill amount is reached - it succeeds and does not fill the rest of the orders.
-     * If fill amount is not reached - it fills as much of the fill amount as possible and succeeds.
-     * @param   signedOrders                                The array of signedOrders that you would like to fill until
-     *                                                      takerTokenFillAmount is reached.
-     * @param   fillTakerTokenAmount                        The total amount of the takerTokens you would like to fill.
-     * @param   shouldThrowOnInsufficientBalanceOrAllowance Whether or not you wish for the contract call to throw if
-     *                                                      upon execution any of the tokens cannot be transferred.
-     *                                                      If set to false, the call will continue to fill subsequent
-     *                                                      signedOrders even when some cannot be filled.
-     * @param   takerAddress                                The user Ethereum address who would like to fill these
-     *                                                      orders. Must be available via the supplied Web3.Provider
-     *                                                      passed to 0x.js.
-     * @param   orderTransactionOpts                        Optional arguments this method accepts.
-     * @return  Transaction hash.
-     */
-    @decorators.contractCallErrorHandler
-    public async fillOrdersUpToAsync(signedOrders: SignedOrder[], fillTakerTokenAmount: BigNumber,
-                                     shouldThrowOnInsufficientBalanceOrAllowance: boolean,
-                                     takerAddress: string,
-                                     orderTransactionOpts?: OrderTransactionOpts): Promise<string> {
-        assert.doesConformToSchema('signedOrders', signedOrders, schemas.signedOrdersSchema);
-        const takerTokenAddresses = _.map(signedOrders, signedOrder => signedOrder.takerTokenAddress);
-        assert.hasAtMostOneUniqueValue(takerTokenAddresses,
-                                       ExchangeContractErrs.MultipleTakerTokensInFillUpToDisallowed);
-        const exchangeContractAddresses = _.map(signedOrders, signedOrder => signedOrder.exchangeContractAddress);
-        assert.hasAtMostOneUniqueValue(exchangeContractAddresses,
-                                       ExchangeContractErrs.BatchOrdersMustHaveSameExchangeAddress);
-        assert.isValidBaseUnitAmount('fillTakerTokenAmount', fillTakerTokenAmount);
-        assert.isBoolean('shouldThrowOnInsufficientBalanceOrAllowance', shouldThrowOnInsufficientBalanceOrAllowance);
-        await assert.isSenderAddressAsync('takerAddress', takerAddress, this._web3Wrapper);
-
-        const shouldValidate = _.isUndefined(orderTransactionOpts) ?
-            SHOULD_VALIDATE_BY_DEFAULT :
-            orderTransactionOpts.shouldValidate;
-        if (shouldValidate) {
-            const zrxTokenAddress = await this.getZRXTokenAddressAsync();
-            const exchangeTradeEmulator = new ExchangeTransferSimulator(this._tokenWrapper);
-            for (const signedOrder of signedOrders) {
-                await this._orderValidationUtils.validateFillOrderThrowIfInvalidAsync(
-                    exchangeTradeEmulator, signedOrder, fillTakerTokenAmount, takerAddress, zrxTokenAddress);
-            }
-        }
-
-        if (_.isEmpty(signedOrders)) {
-            throw new Error(ExchangeContractErrs.BatchOrdersMustHaveAtLeastOneItem);
-        }
-
-        const orderAddressesValuesAndSignatureArray = _.map(signedOrders, signedOrder => {
-            return [
-                ...ExchangeWrapper._getOrderAddressesAndValues(signedOrder),
-                signedOrder.ecSignature.v,
-                signedOrder.ecSignature.r,
-                signedOrder.ecSignature.s,
-            ];
-        });
-        // We use _.unzip<any> because _.unzip doesn't type check if values have different types :'(
-        const [orderAddressesArray, orderValuesArray, vArray, rArray, sArray] = _.unzip<any>(
-            orderAddressesValuesAndSignatureArray,
-        );
-
-        const exchangeInstance = await this._getExchangeContractAsync();
-        const gas = await exchangeInstance.fillOrdersUpTo.estimateGasAsync(
-            orderAddressesArray,
-            orderValuesArray,
-            fillTakerTokenAmount,
-            shouldThrowOnInsufficientBalanceOrAllowance,
-            vArray,
-            rArray,
-            sArray,
-            {
-                from: takerAddress,
-            },
-        );
-        const txHash = await exchangeInstance.fillOrdersUpTo.sendTransactionAsync(
-            orderAddressesArray,
-            orderValuesArray,
-            fillTakerTokenAmount,
-            shouldThrowOnInsufficientBalanceOrAllowance,
-            vArray,
-            rArray,
-            sArray,
-            {
-                from: takerAddress,
-                gas,
-            },
-        );
-        return txHash;
-    }
-    /**
-     * Batch version of fillOrderAsync.
-     * Executes multiple fills atomically in a single transaction.
-     * If shouldThrowOnInsufficientBalanceOrAllowance is set to false, it will continue filling subsequent orders even
-     * when earlier ones fail.
-     * When shouldThrowOnInsufficientBalanceOrAllowance is set to true, if any fill fails, the entire batch fails.
-     * @param   orderFillRequests                               An array of objects that conform to the
-     *                                                          OrderFillRequest interface.
-     * @param   shouldThrowOnInsufficientBalanceOrAllowance     Whether or not you wish for the contract call to throw
-     *                                                          if upon execution any of the tokens cannot be
-     *                                                          transferred. If set to false, the call will continue to
-     *                                                          fill subsequent signedOrders even when some
-     *                                                          cannot be filled.
-     * @param   takerAddress                                    The user Ethereum address who would like to fill
-     *                                                          these orders. Must be available via the supplied
-     *                                                          Web3.Provider passed to 0x.js.
-     * @param   orderTransactionOpts                            Optional arguments this method accepts.
-     * @return  Transaction hash.
-     */
-    @decorators.contractCallErrorHandler
-    public async batchFillOrdersAsync(orderFillRequests: OrderFillRequest[],
-                                      shouldThrowOnInsufficientBalanceOrAllowance: boolean,
-                                      takerAddress: string,
-                                      orderTransactionOpts?: OrderTransactionOpts): Promise<string> {
-        assert.doesConformToSchema('orderFillRequests', orderFillRequests, schemas.orderFillRequestsSchema);
-        const exchangeContractAddresses = _.map(
-            orderFillRequests,
-            orderFillRequest => orderFillRequest.signedOrder.exchangeContractAddress,
-        );
-        assert.hasAtMostOneUniqueValue(exchangeContractAddresses,
-                                       ExchangeContractErrs.BatchOrdersMustHaveSameExchangeAddress);
-        assert.isBoolean('shouldThrowOnInsufficientBalanceOrAllowance', shouldThrowOnInsufficientBalanceOrAllowance);
-        await assert.isSenderAddressAsync('takerAddress', takerAddress, this._web3Wrapper);
-        const shouldValidate = _.isUndefined(orderTransactionOpts) ?
-            SHOULD_VALIDATE_BY_DEFAULT :
-            orderTransactionOpts.shouldValidate;
-        if (shouldValidate) {
-            const zrxTokenAddress = await this.getZRXTokenAddressAsync();
-            const exchangeTradeEmulator = new ExchangeTransferSimulator(this._tokenWrapper);
-            for (const orderFillRequest of orderFillRequests) {
-                await this._orderValidationUtils.validateFillOrderThrowIfInvalidAsync(
-                    exchangeTradeEmulator, orderFillRequest.signedOrder, orderFillRequest.takerTokenFillAmount,
-                    takerAddress, zrxTokenAddress,
-                );
-            }
-        }
-        if (_.isEmpty(orderFillRequests)) {
-            throw new Error(ExchangeContractErrs.BatchOrdersMustHaveAtLeastOneItem);
-        }
-
-        const orderAddressesValuesAmountsAndSignatureArray = _.map(orderFillRequests, orderFillRequest => {
-            return [
-                ...ExchangeWrapper._getOrderAddressesAndValues(orderFillRequest.signedOrder),
-                orderFillRequest.takerTokenFillAmount,
-                orderFillRequest.signedOrder.ecSignature.v,
-                orderFillRequest.signedOrder.ecSignature.r,
-                orderFillRequest.signedOrder.ecSignature.s,
-            ];
-        });
-        // We use _.unzip<any> because _.unzip doesn't type check if values have different types :'(
-        const [orderAddressesArray, orderValuesArray, fillTakerTokenAmounts, vArray, rArray, sArray] = _.unzip<any>(
-            orderAddressesValuesAmountsAndSignatureArray,
-        );
-
-        const exchangeInstance = await this._getExchangeContractAsync();
-        const gas = await exchangeInstance.batchFillOrders.estimateGasAsync(
-            orderAddressesArray,
-            orderValuesArray,
-            fillTakerTokenAmounts,
-            shouldThrowOnInsufficientBalanceOrAllowance,
-            vArray,
-            rArray,
-            sArray,
-            {
-                from: takerAddress,
-            },
-        );
-        const txHash = await exchangeInstance.batchFillOrders.sendTransactionAsync(
-            orderAddressesArray,
-            orderValuesArray,
-            fillTakerTokenAmounts,
-            shouldThrowOnInsufficientBalanceOrAllowance,
-            vArray,
-            rArray,
-            sArray,
-            {
-                from: takerAddress,
-                gas,
-            },
-        );
-        return txHash;
-    }
-    /**
-     * Attempts to fill a specific amount of an order. If the entire amount specified cannot be filled,
-     * the fill order is abandoned.
-     * @param   signedOrder             An object that conforms to the SignedOrder interface. The
-     *                                  signedOrder you wish to fill.
-     * @param   fillTakerTokenAmount    The total amount of the takerTokens you would like to fill.
-     * @param   takerAddress            The user Ethereum address who would like to fill this order.
-     *                                  Must be available via the supplied Web3.Provider passed to 0x.js.
-     * @param   orderTransactionOpts    Optional arguments this method accepts.
-     * @return  Transaction hash.
-     */
-    @decorators.contractCallErrorHandler
-    public async fillOrKillOrderAsync(signedOrder: SignedOrder, fillTakerTokenAmount: BigNumber,
-                                      takerAddress: string,
-                                      orderTransactionOpts?: OrderTransactionOpts): Promise<string> {
-        assert.doesConformToSchema('signedOrder', signedOrder, schemas.signedOrderSchema);
-        assert.isValidBaseUnitAmount('fillTakerTokenAmount', fillTakerTokenAmount);
-        await assert.isSenderAddressAsync('takerAddress', takerAddress, this._web3Wrapper);
-
-        const exchangeInstance = await this._getExchangeContractAsync();
-
-        const shouldValidate = _.isUndefined(orderTransactionOpts) ?
-            SHOULD_VALIDATE_BY_DEFAULT :
-            orderTransactionOpts.shouldValidate;
-        if (shouldValidate) {
-            const zrxTokenAddress = await this.getZRXTokenAddressAsync();
-            const exchangeTradeEmulator = new ExchangeTransferSimulator(this._tokenWrapper);
-            await this._orderValidationUtils.validateFillOrKillOrderThrowIfInvalidAsync(
-                exchangeTradeEmulator, signedOrder, fillTakerTokenAmount, takerAddress, zrxTokenAddress);
-        }
-
-        const [orderAddresses, orderValues] = ExchangeWrapper._getOrderAddressesAndValues(signedOrder);
-
-        const gas = await exchangeInstance.fillOrKillOrder.estimateGasAsync(
-            orderAddresses,
-            orderValues,
-            fillTakerTokenAmount,
-            signedOrder.ecSignature.v,
-            signedOrder.ecSignature.r,
-            signedOrder.ecSignature.s,
-            {
-                from: takerAddress,
-            },
-        );
-        const txHash = await exchangeInstance.fillOrKillOrder.sendTransactionAsync(
-            orderAddresses,
-            orderValues,
-            fillTakerTokenAmount,
-            signedOrder.ecSignature.v,
-            signedOrder.ecSignature.r,
-            signedOrder.ecSignature.s,
-            {
-                from: takerAddress,
-                gas,
-            },
-        );
-        return txHash;
-    }
-    /**
-     * Batch version of fillOrKill. Allows a taker to specify a batch of orders that will either be atomically
-     * filled (each to the specified fillAmount) or aborted.
-     * @param   orderFillRequests           An array of objects that conform to the OrderFillRequest interface.
-     * @param   takerAddress                The user Ethereum address who would like to fill there orders.
-     *                                      Must be available via the supplied Web3.Provider passed to 0x.js.
-     * @param   orderTransactionOpts        Optional arguments this method accepts.
-     * @return  Transaction hash.
-     */
-    @decorators.contractCallErrorHandler
-    public async batchFillOrKillAsync(orderFillRequests: OrderFillRequest[],
-                                      takerAddress: string,
-                                      orderTransactionOpts?: OrderTransactionOpts): Promise<string> {
-        assert.doesConformToSchema('orderFillRequests', orderFillRequests,
-                                   schemas.orderFillRequestsSchema);
-        const exchangeContractAddresses = _.map(
-            orderFillRequests,
-            orderFillRequest => orderFillRequest.signedOrder.exchangeContractAddress,
-        );
-        assert.hasAtMostOneUniqueValue(exchangeContractAddresses,
-                                       ExchangeContractErrs.BatchOrdersMustHaveSameExchangeAddress);
-        await assert.isSenderAddressAsync('takerAddress', takerAddress, this._web3Wrapper);
-        if (_.isEmpty(orderFillRequests)) {
-            throw new Error(ExchangeContractErrs.BatchOrdersMustHaveAtLeastOneItem);
-        }
-        const exchangeInstance = await this._getExchangeContractAsync();
-
-        const shouldValidate = _.isUndefined(orderTransactionOpts) ?
-            SHOULD_VALIDATE_BY_DEFAULT :
-            orderTransactionOpts.shouldValidate;
-        if (shouldValidate) {
-            const zrxTokenAddress = await this.getZRXTokenAddressAsync();
-            const exchangeTradeEmulator = new ExchangeTransferSimulator(this._tokenWrapper);
-            for (const orderFillRequest of orderFillRequests) {
-                await this._orderValidationUtils.validateFillOrKillOrderThrowIfInvalidAsync(
-                    exchangeTradeEmulator, orderFillRequest.signedOrder, orderFillRequest.takerTokenFillAmount,
-                    takerAddress, zrxTokenAddress,
-                );
-            }
-        }
-
-        const orderAddressesValuesAndTakerTokenFillAmounts = _.map(orderFillRequests, request => {
-            return [
-                ...ExchangeWrapper._getOrderAddressesAndValues(request.signedOrder),
-                request.takerTokenFillAmount,
-                request.signedOrder.ecSignature.v,
-                request.signedOrder.ecSignature.r,
-                request.signedOrder.ecSignature.s,
-            ];
-        });
-
-        // We use _.unzip<any> because _.unzip doesn't type check if values have different types :'(
-        const [orderAddresses, orderValues, fillTakerTokenAmounts, vParams, rParams, sParams] =
-              _.unzip<any>(orderAddressesValuesAndTakerTokenFillAmounts);
-
-        const gas = await exchangeInstance.batchFillOrKillOrders.estimateGasAsync(
-            orderAddresses,
-            orderValues,
-            fillTakerTokenAmounts,
-            vParams,
-            rParams,
-            sParams,
-            {
-                from: takerAddress,
-            },
-        );
-        const txHash = await exchangeInstance.batchFillOrKillOrders.sendTransactionAsync(
-            orderAddresses,
-            orderValues,
-            fillTakerTokenAmounts,
-            vParams,
-            rParams,
-            sParams,
-            {
-                from: takerAddress,
-                gas,
-            },
-        );
-        return txHash;
-    }
-    /**
-     * Cancel a given fill amount of an order. Cancellations are cumulative.
-     * @param   order                   An object that conforms to the Order or SignedOrder interface.
-     *                                  The order you would like to cancel.
-     * @param   cancelTakerTokenAmount  The amount (specified in taker tokens) that you would like to cancel.
-     * @param   transactionOpts         Optional arguments this method accepts.
-     * @return  Transaction hash.
-     */
-    @decorators.contractCallErrorHandler
-    public async cancelOrderAsync(order: Order|SignedOrder,
-                                  cancelTakerTokenAmount: BigNumber,
-                                  orderTransactionOpts?: OrderTransactionOpts): Promise<string> {
-        assert.doesConformToSchema('order', order, schemas.orderSchema);
-        assert.isValidBaseUnitAmount('takerTokenCancelAmount', cancelTakerTokenAmount);
-        await assert.isSenderAddressAsync('order.maker', order.maker, this._web3Wrapper);
-
-        const exchangeInstance = await this._getExchangeContractAsync();
-
-        const shouldValidate = _.isUndefined(orderTransactionOpts) ?
-            SHOULD_VALIDATE_BY_DEFAULT :
-            orderTransactionOpts.shouldValidate;
-        if (shouldValidate) {
-            const orderHash = utils.getOrderHashHex(order);
-            const unavailableTakerTokenAmount = await this.getUnavailableTakerAmountAsync(orderHash);
-            await this._orderValidationUtils.validateCancelOrderThrowIfInvalidAsync(
-                order, cancelTakerTokenAmount, unavailableTakerTokenAmount);
-        }
-
-        const [orderAddresses, orderValues] = ExchangeWrapper._getOrderAddressesAndValues(order);
-        const gas = await exchangeInstance.cancelOrder.estimateGasAsync(
-            orderAddresses,
-            orderValues,
-            cancelTakerTokenAmount,
-            {
-                from: order.maker,
-            },
-        );
-        const txHash = await exchangeInstance.cancelOrder.sendTransactionAsync(
-            orderAddresses,
-            orderValues,
-            cancelTakerTokenAmount,
-            {
-                from: order.maker,
-                gas,
-            },
-        );
-        return txHash;
-    }
-    /**
-     * Batch version of cancelOrderAsync. Atomically cancels multiple orders in a single transaction.
-     * All orders must be from the same maker.
-     * @param   orderCancellationRequests   An array of objects that conform to the OrderCancellationRequest
-     *                                      interface.
-     * @param   transactionOpts             Optional arguments this method accepts.
-     * @return  Transaction hash.
-     */
-    @decorators.contractCallErrorHandler
-    public async batchCancelOrdersAsync(orderCancellationRequests: OrderCancellationRequest[],
-                                        orderTransactionOpts?: OrderTransactionOpts): Promise<string> {
-        assert.doesConformToSchema('orderCancellationRequests', orderCancellationRequests,
-                                   schemas.orderCancellationRequestsSchema);
-        const exchangeContractAddresses = _.map(
-            orderCancellationRequests,
-            orderCancellationRequest => orderCancellationRequest.order.exchangeContractAddress,
-        );
-        assert.hasAtMostOneUniqueValue(exchangeContractAddresses,
-                                       ExchangeContractErrs.BatchOrdersMustHaveSameExchangeAddress);
-        const makers = _.map(orderCancellationRequests, cancellationRequest => cancellationRequest.order.maker);
-        assert.hasAtMostOneUniqueValue(makers, ExchangeContractErrs.MultipleMakersInSingleCancelBatchDisallowed);
-        const maker = makers[0];
-        await assert.isSenderAddressAsync('maker', maker, this._web3Wrapper);
-        const shouldValidate = _.isUndefined(orderTransactionOpts) ?
-            SHOULD_VALIDATE_BY_DEFAULT :
-            orderTransactionOpts.shouldValidate;
-        if (shouldValidate) {
-            for (const orderCancellationRequest of orderCancellationRequests) {
-                const orderHash = utils.getOrderHashHex(orderCancellationRequest.order);
-                const unavailableTakerTokenAmount = await this.getUnavailableTakerAmountAsync(orderHash);
-                await this._orderValidationUtils.validateCancelOrderThrowIfInvalidAsync(
-                    orderCancellationRequest.order, orderCancellationRequest.takerTokenCancelAmount,
-                    unavailableTakerTokenAmount,
-                );
-            }
-
-        }
-        if (_.isEmpty(orderCancellationRequests)) {
-            throw new Error(ExchangeContractErrs.BatchOrdersMustHaveAtLeastOneItem);
-        }
-        const exchangeInstance = await this._getExchangeContractAsync();
-        const orderAddressesValuesAndTakerTokenCancelAmounts = _.map(orderCancellationRequests, cancellationRequest => {
-            return [
-                ...ExchangeWrapper._getOrderAddressesAndValues(cancellationRequest.order),
-                cancellationRequest.takerTokenCancelAmount,
-            ];
-        });
-        // We use _.unzip<any> because _.unzip doesn't type check if values have different types :'(
-        const [orderAddresses, orderValues, cancelTakerTokenAmounts] =
-            _.unzip<any>(orderAddressesValuesAndTakerTokenCancelAmounts);
-        const gas = await exchangeInstance.batchCancelOrders.estimateGasAsync(
-            orderAddresses,
-            orderValues,
-            cancelTakerTokenAmounts,
-            {
-                from: maker,
-            },
-        );
-        const txHash = await exchangeInstance.batchCancelOrders.sendTransactionAsync(
-            orderAddresses,
-            orderValues,
-            cancelTakerTokenAmounts,
-            {
-                from: maker,
-                gas,
-            },
-        );
-        return txHash;
-    }
-    /**
-     * Subscribe to an event type emitted by the Exchange contract.
-     * @param   eventName           The exchange contract event you would like to subscribe to.
-     * @param   indexFilterValues   An object where the keys are indexed args returned by the event and
-     *                              the value is the value you are interested in. E.g `{maker: aUserAddressHex}`
-     * @param   callback            Callback that gets called when a log is added/removed
-     * @return Subscription token used later to unsubscribe
-     */
-    public async subscribeAsync<ArgsType extends ExchangeContractEventArgs>(
-        eventName: ExchangeEvents, indexFilterValues: IndexedFilterValues,
-        callback: EventCallback<ArgsType>): Promise<string> {
-        assert.doesBelongToStringEnum('eventName', eventName, ExchangeEvents);
-        assert.doesConformToSchema('indexFilterValues', indexFilterValues, schemas.indexFilterValuesSchema);
-        assert.isFunction('callback', callback);
-        const exchangeContractAddress = await this.getContractAddressAsync();
-        const subscriptionToken = this._subscribe<ArgsType>(
-            exchangeContractAddress, eventName, indexFilterValues, artifacts.ExchangeArtifact.abi, callback,
-        );
-        return subscriptionToken;
-    }
-    /**
-     * Cancel a subscription
-     * @param   subscriptionToken Subscription token returned by `subscribe()`
-     */
-    public unsubscribe(subscriptionToken: string): void {
-        this._unsubscribe(subscriptionToken);
-    }
-    /**
-     * Gets historical logs without creating a subscription
-     * @param   eventName           The exchange contract event you would like to subscribe to.
-     * @param   subscriptionOpts    Subscriptions options that let you configure the subscription.
-     * @param   indexFilterValues   An object where the keys are indexed args returned by the event and
-     *                              the value is the value you are interested in. E.g `{_from: aUserAddressHex}`
-     * @return  Array of logs that match the parameters
-     */
-    public async getLogsAsync<ArgsType extends ExchangeContractEventArgs>(
-        eventName: ExchangeEvents, subscriptionOpts: SubscriptionOpts, indexFilterValues: IndexedFilterValues,
-    ): Promise<Array<LogWithDecodedArgs<ArgsType>>> {
-        assert.doesBelongToStringEnum('eventName', eventName, ExchangeEvents);
-        assert.doesConformToSchema('subscriptionOpts', subscriptionOpts, schemas.subscriptionOptsSchema);
-        assert.doesConformToSchema('indexFilterValues', indexFilterValues, schemas.indexFilterValuesSchema);
-        const exchangeContractAddress = await this.getContractAddressAsync();
-        const logs = await this._getLogsAsync<ArgsType>(
-            exchangeContractAddress, eventName, subscriptionOpts, indexFilterValues, artifacts.ExchangeArtifact.abi,
-        );
-        return logs;
-    }
-    /**
-     * Retrieves the Ethereum address of the Exchange contract deployed on the network
-     * that the user-passed web3 provider is connected to.
-     * @returns The Ethereum address of the Exchange contract being used.
-     */
-    public async getContractAddressAsync(): Promise<string> {
-        const exchangeInstance = await this._getExchangeContractAsync();
-        const exchangeAddress = exchangeInstance.address;
-        return exchangeAddress;
-    }
-    /**
-     * Checks if order is still fillable and throws an error otherwise. Useful for orderbook
-     * pruning where you want to remove stale orders without knowing who the taker will be.
-     * @param   signedOrder     An object that conforms to the SignedOrder interface. The
-     *                          signedOrder you wish to validate.
-     * @param   opts            An object that conforms to the ValidateOrderFillableOpts
-     *                          interface. Allows specifying a specific fillTakerTokenAmount
-     *                          to validate for.
-     */
-    public async validateOrderFillableOrThrowAsync(
-        signedOrder: SignedOrder, opts?: ValidateOrderFillableOpts,
-    ): Promise<void> {
-        assert.doesConformToSchema('signedOrder', signedOrder, schemas.signedOrderSchema);
-        const zrxTokenAddress = await this.getZRXTokenAddressAsync();
-        const expectedFillTakerTokenAmount = !_.isUndefined(opts) ? opts.expectedFillTakerTokenAmount : undefined;
-        const exchangeTradeEmulator = new ExchangeTransferSimulator(this._tokenWrapper);
-        await this._orderValidationUtils.validateOrderFillableOrThrowAsync(
-            exchangeTradeEmulator, signedOrder, zrxTokenAddress, expectedFillTakerTokenAmount,
-        );
-    }
-    /**
-     * Checks if order fill will succeed and throws an error otherwise.
-     * @param   signedOrder             An object that conforms to the SignedOrder interface. The
-     *                                  signedOrder you wish to fill.
-     * @param   fillTakerTokenAmount    The total amount of the takerTokens you would like to fill.
-     * @param   takerAddress            The user Ethereum address who would like to fill this order.
-     *                                  Must be available via the supplied Web3.Provider passed to 0x.js.
-     */
-    public async validateFillOrderThrowIfInvalidAsync(signedOrder: SignedOrder,
-                                                      fillTakerTokenAmount: BigNumber,
-                                                      takerAddress: string): Promise<void> {
-        assert.doesConformToSchema('signedOrder', signedOrder, schemas.signedOrderSchema);
-        assert.isValidBaseUnitAmount('fillTakerTokenAmount', fillTakerTokenAmount);
-        await assert.isSenderAddressAsync('takerAddress', takerAddress, this._web3Wrapper);
-        const zrxTokenAddress = await this.getZRXTokenAddressAsync();
-        const exchangeTradeEmulator = new ExchangeTransferSimulator(this._tokenWrapper);
-        await this._orderValidationUtils.validateFillOrderThrowIfInvalidAsync(
-            exchangeTradeEmulator, signedOrder, fillTakerTokenAmount, takerAddress, zrxTokenAddress);
-    }
-    /**
-     * Checks if cancelling a given order will succeed and throws an informative error if it won't.
-     * @param   order                   An object that conforms to the Order or SignedOrder interface.
-     *                                  The order you would like to cancel.
-     * @param   cancelTakerTokenAmount  The amount (specified in taker tokens) that you would like to cancel.
-     */
-    public async validateCancelOrderThrowIfInvalidAsync(
-        order: Order, cancelTakerTokenAmount: BigNumber): Promise<void> {
-        assert.doesConformToSchema('order', order, schemas.orderSchema);
-        assert.isValidBaseUnitAmount('cancelTakerTokenAmount', cancelTakerTokenAmount);
-        const orderHash = utils.getOrderHashHex(order);
-        const unavailableTakerTokenAmount = await this.getUnavailableTakerAmountAsync(orderHash);
-        await this._orderValidationUtils.validateCancelOrderThrowIfInvalidAsync(
-            order, cancelTakerTokenAmount, unavailableTakerTokenAmount);
-    }
-    /**
-     * Checks if calling fillOrKill on a given order will succeed and throws an informative error if it won't.
-     * @param   signedOrder             An object that conforms to the SignedOrder interface. The
-     *                                  signedOrder you wish to fill.
-     * @param   fillTakerTokenAmount    The total amount of the takerTokens you would like to fill.
-     * @param   takerAddress            The user Ethereum address who would like to fill this order.
-     *                                  Must be available via the supplied Web3.Provider passed to 0x.js.
-     */
-    public async validateFillOrKillOrderThrowIfInvalidAsync(signedOrder: SignedOrder,
-                                                            fillTakerTokenAmount: BigNumber,
-                                                            takerAddress: string): Promise<void> {
-        assert.doesConformToSchema('signedOrder', signedOrder, schemas.signedOrderSchema);
-        assert.isValidBaseUnitAmount('fillTakerTokenAmount', fillTakerTokenAmount);
-        await assert.isSenderAddressAsync('takerAddress', takerAddress, this._web3Wrapper);
-        const zrxTokenAddress = await this.getZRXTokenAddressAsync();
-        const exchangeTradeEmulator = new ExchangeTransferSimulator(this._tokenWrapper);
-        await this._orderValidationUtils.validateFillOrKillOrderThrowIfInvalidAsync(
-            exchangeTradeEmulator, signedOrder, fillTakerTokenAmount, takerAddress, zrxTokenAddress);
-    }
-    /**
-     * Checks if rounding error will be > 0.1% when computing makerTokenAmount by doing:
-     * `(fillTakerTokenAmount * makerTokenAmount) / takerTokenAmount`.
-     * 0x Protocol does not accept any trades that result in large rounding errors. This means that tokens with few or
-     * no decimals can only be filled in quantities and ratios that avoid large rounding errors.
-     * @param   fillTakerTokenAmount   The amount of the order (in taker tokens baseUnits) that you wish to fill.
-     * @param   takerTokenAmount       The order size on the taker side
-     * @param   makerTokenAmount       The order size on the maker side
-     */
-    public async isRoundingErrorAsync(fillTakerTokenAmount: BigNumber,
-                                      takerTokenAmount: BigNumber,
-                                      makerTokenAmount: BigNumber): Promise<boolean> {
-        assert.isValidBaseUnitAmount('fillTakerTokenAmount', fillTakerTokenAmount);
-        assert.isValidBaseUnitAmount('takerTokenAmount', takerTokenAmount);
-        assert.isValidBaseUnitAmount('makerTokenAmount', makerTokenAmount);
-        const exchangeInstance = await this._getExchangeContractAsync();
-        const isRoundingError = await exchangeInstance.isRoundingError.callAsync(
-            fillTakerTokenAmount, takerTokenAmount, makerTokenAmount,
-        );
-        return isRoundingError;
-    }
-    /**
-     * Checks if logs contain LogError, which is emmited by Exchange contract on transaction failure.
-     * @param   logs   Transaction logs as returned by `zeroEx.awaitTransactionMinedAsync`
-     */
-    public throwLogErrorsAsErrors(logs: Array<LogWithDecodedArgs<DecodedLogArgs>|Web3.LogEntry>): void {
-        const errLog = _.find(logs, {
-            event: ExchangeEvents.LogError,
-        }) as LogWithDecodedArgs<LogErrorContractEventArgs>|undefined;
-        if (!_.isUndefined(errLog)) {
-            const logArgs = errLog.args;
-            const errCode = logArgs.errorId.toNumber();
-            const errMessage = this._exchangeContractErrCodesToMsg[errCode];
-            throw new Error(errMessage);
-        }
-    }
-    /**
-     * Returns the ZRX token address used by the exchange contract.
-     * @return Address of ZRX token
-     */
-    public async getZRXTokenAddressAsync(): Promise<string> {
-        const exchangeInstance = await this._getExchangeContractAsync();
-        const ZRXtokenAddress = await exchangeInstance.ZRX_TOKEN_CONTRACT.callAsync();
-        return ZRXtokenAddress;
-    }
-    private async _invalidateContractInstancesAsync(): Promise<void> {
-        this.unsubscribeAll();
-        delete this._exchangeContractIfExists;
-    }
-    private async _isValidSignatureUsingContractCallAsync(dataHex: string, ecSignature: ECSignature,
-                                                          signerAddressHex: string): Promise<boolean> {
-        assert.isHexString('dataHex', dataHex);
-        assert.doesConformToSchema('ecSignature', ecSignature, schemas.ecSignatureSchema);
-        assert.isETHAddressHex('signerAddressHex', signerAddressHex);
-
-        const exchangeInstance = await this._getExchangeContractAsync();
-
-        const isValidSignature = await exchangeInstance.isValidSignature.callAsync(
-            signerAddressHex,
-            dataHex,
-            ecSignature.v,
-            ecSignature.r,
-            ecSignature.s,
-        );
-        return isValidSignature;
-    }
-    private async _getOrderHashHexUsingContractCallAsync(order: Order|SignedOrder): Promise<string> {
-        const exchangeInstance = await this._getExchangeContractAsync();
-        const [orderAddresses, orderValues] = ExchangeWrapper._getOrderAddressesAndValues(order);
-        const orderHashHex = await exchangeInstance.getOrderHash.callAsync(orderAddresses, orderValues);
-        return orderHashHex;
-    }
-    private async _getExchangeContractAsync(): Promise<ExchangeContract> {
-        if (!_.isUndefined(this._exchangeContractIfExists)) {
-            return this._exchangeContractIfExists;
-        }
-        const contractInstance = await this._instantiateContractIfExistsAsync<ExchangeContract>(
-            artifacts.ExchangeArtifact, this._contractAddressIfExists,
-        );
-        this._exchangeContractIfExists = contractInstance as ExchangeContract;
-        return this._exchangeContractIfExists;
-    }
-    private async _getTokenTransferProxyAddressAsync(): Promise<string> {
-        const exchangeInstance = await this._getExchangeContractAsync();
-        const tokenTransferProxyAddress = await exchangeInstance.TOKEN_TRANSFER_PROXY_CONTRACT.callAsync();
-        const tokenTransferProxyAddressLowerCase = tokenTransferProxyAddress.toLowerCase();
-        return tokenTransferProxyAddressLowerCase;
-    }
-}
diff --git a/src/contract_wrappers/token_registry_wrapper.ts b/src/contract_wrappers/token_registry_wrapper.ts
deleted file mode 100644
index 2cc5a9aa0..000000000
--- a/src/contract_wrappers/token_registry_wrapper.ts
+++ /dev/null
@@ -1,122 +0,0 @@
-import * as _ from 'lodash';
-import {Web3Wrapper} from '../web3_wrapper';
-import {assert} from '../utils/assert';
-import {Token, TokenRegistryContract, TokenMetadata} from '../types';
-import {constants} from '../utils/constants';
-import {ContractWrapper} from './contract_wrapper';
-import {artifacts} from '../artifacts';
-
-/**
- * This class includes all the functionality related to interacting with the 0x Token Registry smart contract.
- */
-export class TokenRegistryWrapper extends ContractWrapper {
-    private _tokenRegistryContractIfExists?: TokenRegistryContract;
-    private _contractAddressIfExists?: string;
-    constructor(web3Wrapper: Web3Wrapper, contractAddressIfExists?: string) {
-        super(web3Wrapper);
-        this._contractAddressIfExists = contractAddressIfExists;
-    }
-    /**
-     * Retrieves all the tokens currently listed in the Token Registry smart contract
-     * @return  An array of objects that conform to the Token interface.
-     */
-    public async getTokensAsync(): Promise<Token[]> {
-        const tokenRegistryContract = await this._getTokenRegistryContractAsync();
-
-        const addresses = await this.getTokenAddressesAsync();
-        const tokenPromises: Array<Promise<Token|undefined>> = _.map(
-            addresses,
-            (address: string) => (this.getTokenIfExistsAsync(address)),
-        );
-        const tokens = await Promise.all(tokenPromises);
-        return tokens as Token[];
-    }
-    /**
-     * Retrieves all the addresses of the tokens currently listed in the Token Registry smart contract
-     * @return  An array of token addresses.
-     */
-    public async getTokenAddressesAsync(): Promise<string[]> {
-        const tokenRegistryContract = await this._getTokenRegistryContractAsync();
-        const addresses = await tokenRegistryContract.getTokenAddresses.callAsync();
-        return addresses;
-    }
-    /**
-     * Retrieves a token by address currently listed in the Token Registry smart contract
-     * @return  An object that conforms to the Token interface or undefined if token not found.
-     */
-    public async getTokenIfExistsAsync(address: string): Promise<Token|undefined> {
-        assert.isETHAddressHex('address', address);
-
-        const tokenRegistryContract = await this._getTokenRegistryContractAsync();
-        const metadata = await tokenRegistryContract.getTokenMetaData.callAsync(address);
-        const token = this._createTokenFromMetadata(metadata);
-        return token;
-    }
-    public async getTokenAddressBySymbolIfExistsAsync(symbol: string): Promise<string|undefined> {
-        assert.isString('symbol', symbol);
-        const tokenRegistryContract = await this._getTokenRegistryContractAsync();
-        const addressIfExists = await tokenRegistryContract.getTokenAddressBySymbol.callAsync(symbol);
-        if (addressIfExists === constants.NULL_ADDRESS) {
-            return undefined;
-        }
-        return addressIfExists;
-    }
-    public async getTokenAddressByNameIfExistsAsync(name: string): Promise<string|undefined> {
-        assert.isString('name', name);
-        const tokenRegistryContract = await this._getTokenRegistryContractAsync();
-        const addressIfExists = await tokenRegistryContract.getTokenAddressByName.callAsync(name);
-        if (addressIfExists === constants.NULL_ADDRESS) {
-            return undefined;
-        }
-        return addressIfExists;
-    }
-    public async getTokenBySymbolIfExistsAsync(symbol: string): Promise<Token|undefined> {
-        assert.isString('symbol', symbol);
-        const tokenRegistryContract = await this._getTokenRegistryContractAsync();
-        const metadata = await tokenRegistryContract.getTokenBySymbol.callAsync(symbol);
-        const token = this._createTokenFromMetadata(metadata);
-        return token;
-    }
-    public async getTokenByNameIfExistsAsync(name: string): Promise<Token|undefined> {
-        assert.isString('name', name);
-        const tokenRegistryContract = await this._getTokenRegistryContractAsync();
-        const metadata = await tokenRegistryContract.getTokenByName.callAsync(name);
-        const token = this._createTokenFromMetadata(metadata);
-        return token;
-    }
-    /**
-     * Retrieves the Ethereum address of the TokenRegistry contract deployed on the network
-     * that the user-passed web3 provider is connected to.
-     * @returns The Ethereum address of the TokenRegistry contract being used.
-     */
-    public async getContractAddressAsync(): Promise<string> {
-        const tokenRegistryInstance = await this._getTokenRegistryContractAsync();
-        const tokenRegistryAddress = tokenRegistryInstance.address;
-        return tokenRegistryAddress;
-    }
-    private _createTokenFromMetadata(metadata: TokenMetadata): Token|undefined {
-        if (metadata[0] === constants.NULL_ADDRESS) {
-            return undefined;
-        }
-        const token = {
-            address: metadata[0],
-            name: metadata[1],
-            symbol: metadata[2],
-            decimals: metadata[3].toNumber(),
-        };
-        return token;
-    }
-    private _invalidateContractInstance(): void {
-        delete this._tokenRegistryContractIfExists;
-    }
-    private async _getTokenRegistryContractAsync(): Promise<TokenRegistryContract> {
-        if (!_.isUndefined(this._tokenRegistryContractIfExists)) {
-            return this._tokenRegistryContractIfExists;
-        }
-        const contractInstance = await this._instantiateContractIfExistsAsync<TokenRegistryContract>(
-            artifacts.TokenRegistryArtifact, this._contractAddressIfExists,
-        );
-        this._tokenRegistryContractIfExists = contractInstance as TokenRegistryContract;
-        return this._tokenRegistryContractIfExists;
-    }
-}
diff --git a/src/contract_wrappers/token_transfer_proxy_wrapper.ts b/src/contract_wrappers/token_transfer_proxy_wrapper.ts
deleted file mode 100644
index f81845af9..000000000
--- a/src/contract_wrappers/token_transfer_proxy_wrapper.ts
+++ /dev/null
@@ -1,60 +0,0 @@
-import * as _ from 'lodash';
-import {Web3Wrapper} from '../web3_wrapper';
-import {ContractWrapper} from './contract_wrapper';
-import {artifacts} from '../artifacts';
-import {TokenTransferProxyContract} from '../types';
-
-/**
- * This class includes the functionality related to interacting with the TokenTransferProxy contract.
- */
-export class TokenTransferProxyWrapper extends ContractWrapper {
-    private _tokenTransferProxyContractIfExists?: TokenTransferProxyContract;
-    private _tokenTransferProxyContractAddressFetcher: () => Promise<string>;
-    constructor(web3Wrapper: Web3Wrapper, tokenTransferProxyContractAddressFetcher: () => Promise<string>) {
-        super(web3Wrapper);
-        this._tokenTransferProxyContractAddressFetcher = tokenTransferProxyContractAddressFetcher;
-    }
-    /**
-     * Check if the Exchange contract address is authorized by the TokenTransferProxy contract.
-     * @param   exchangeContractAddress     The hex encoded address of the Exchange contract to call.
-     * @return  Whether the exchangeContractAddress is authorized.
-     */
-    public async isAuthorizedAsync(exchangeContractAddress: string): Promise<boolean> {
-        const tokenTransferProxyContractInstance = await this._getTokenTransferProxyContractAsync();
-        const isAuthorized = await tokenTransferProxyContractInstance.authorized.callAsync(exchangeContractAddress);
-        return isAuthorized;
-    }
-    /**
-     * Get the list of all Exchange contract addresses authorized by the TokenTransferProxy contract.
-     * @return  The list of authorized addresses.
-     */
-    public async getAuthorizedAddressesAsync(): Promise<string[]> {
-        const tokenTransferProxyContractInstance = await this._getTokenTransferProxyContractAsync();
-        const authorizedAddresses = await tokenTransferProxyContractInstance.getAuthorizedAddresses.callAsync();
-        return authorizedAddresses;
-    }
-    /**
-     * Retrieves the Ethereum address of the TokenTransferProxy contract deployed on the network
-     * that the user-passed web3 provider is connected to.
-     * @returns The Ethereum address of the TokenTransferProxy contract being used.
-     */
-    public async getContractAddressAsync(): Promise<string> {
-        const proxyInstance = await this._getTokenTransferProxyContractAsync();
-        const proxyAddress = proxyInstance.address;
-        return proxyAddress;
-    }
-    private _invalidateContractInstance(): void {
-        delete this._tokenTransferProxyContractIfExists;
-    }
-    private async _getTokenTransferProxyContractAsync(): Promise<TokenTransferProxyContract> {
-        if (!_.isUndefined(this._tokenTransferProxyContractIfExists)) {
-            return this._tokenTransferProxyContractIfExists;
-        }
-        const contractAddress = await this._tokenTransferProxyContractAddressFetcher();
-        const contractInstance = await this._instantiateContractIfExistsAsync<TokenTransferProxyContract>(
-            artifacts.TokenTransferProxyArtifact, contractAddress,
-        );
-        this._tokenTransferProxyContractIfExists = contractInstance as TokenTransferProxyContract;
-        return this._tokenTransferProxyContractIfExists;
-    }
-}
diff --git a/src/contract_wrappers/token_wrapper.ts b/src/contract_wrappers/token_wrapper.ts
deleted file mode 100644
index 614ac19d4..000000000
--- a/src/contract_wrappers/token_wrapper.ts
+++ /dev/null
@@ -1,313 +0,0 @@
-import * as _ from 'lodash';
-import BigNumber from 'bignumber.js';
-import {schemas} from '0x-json-schemas';
-import {Web3Wrapper} from '../web3_wrapper';
-import {assert} from '../utils/assert';
-import {constants} from '../utils/constants';
-import {ContractWrapper} from './contract_wrapper';
-import {AbiDecoder} from '../utils/abi_decoder';
-import {artifacts} from '../artifacts';
-import {
-    TokenContract,
-    ZeroExError,
-    TokenEvents,
-    IndexedFilterValues,
-    SubscriptionOpts,
-    MethodOpts,
-    LogWithDecodedArgs,
-    EventCallback,
-    TokenContractEventArgs,
-} from '../types';
-
-const ALLOWANCE_TO_ZERO_GAS_AMOUNT = 47275;
-
-/**
- * This class includes all the functionality related to interacting with ERC20 token contracts.
- * All ERC20 method calls are supported, along with some convenience methods for getting/setting allowances
- * to the 0x Proxy smart contract.
- */
-export class TokenWrapper extends ContractWrapper {
-    public UNLIMITED_ALLOWANCE_IN_BASE_UNITS = constants.UNLIMITED_ALLOWANCE_IN_BASE_UNITS;
-    private _tokenContractsByAddress: {[address: string]: TokenContract};
-    private _tokenTransferProxyContractAddressFetcher: () => Promise<string>;
-    constructor(web3Wrapper: Web3Wrapper, abiDecoder: AbiDecoder,
-                tokenTransferProxyContractAddressFetcher: () => Promise<string>) {
-        super(web3Wrapper, abiDecoder);
-        this._tokenContractsByAddress = {};
-        this._tokenTransferProxyContractAddressFetcher = tokenTransferProxyContractAddressFetcher;
-    }
-    /**
-     * Retrieves an owner's ERC20 token balance.
-     * @param   tokenAddress    The hex encoded contract Ethereum address where the ERC20 token is deployed.
-     * @param   ownerAddress    The hex encoded user Ethereum address whose balance you would like to check.
-     * @param   methodOpts      Optional arguments this method accepts.
-     * @return  The owner's ERC20 token balance in base units.
-     */
-    public async getBalanceAsync(tokenAddress: string, ownerAddress: string,
-                                 methodOpts?: MethodOpts): Promise<BigNumber> {
-        assert.isETHAddressHex('ownerAddress', ownerAddress);
-        assert.isETHAddressHex('tokenAddress', tokenAddress);
-
-        const tokenContract = await this._getTokenContractAsync(tokenAddress);
-        const defaultBlock = _.isUndefined(methodOpts) ? undefined : methodOpts.defaultBlock;
-        let balance = await tokenContract.balanceOf.callAsync(ownerAddress, defaultBlock);
-        // Wrap BigNumbers returned from web3 with our own (later) version of BigNumber
-        balance = new BigNumber(balance);
-        return balance;
-    }
-    /**
-     * Sets the spender's allowance to a specified number of baseUnits on behalf of the owner address.
-     * Equivalent to the ERC20 spec method `approve`.
-     * @param   tokenAddress        The hex encoded contract Ethereum address where the ERC20 token is deployed.
-     * @param   ownerAddress        The hex encoded user Ethereum address who would like to set an allowance
-     *                              for spenderAddress.
-     * @param   spenderAddress      The hex encoded user Ethereum address who will be able to spend the set allowance.
-     * @param   amountInBaseUnits   The allowance amount you would like to set.
-     * @return Transaction hash.
-     */
-    public async setAllowanceAsync(tokenAddress: string, ownerAddress: string, spenderAddress: string,
-                                   amountInBaseUnits: BigNumber): Promise<string> {
-        await assert.isSenderAddressAsync('ownerAddress', ownerAddress, this._web3Wrapper);
-        assert.isETHAddressHex('spenderAddress', spenderAddress);
-        assert.isETHAddressHex('tokenAddress', tokenAddress);
-        assert.isValidBaseUnitAmount('amountInBaseUnits', amountInBaseUnits);
-
-        const tokenContract = await this._getTokenContractAsync(tokenAddress);
-        // Hack: for some reason default estimated gas amount causes `base fee exceeds gas limit` exception
-        // on testrpc. Probably related to https://github.com/ethereumjs/testrpc/issues/294
-        // TODO: Debug issue in testrpc and submit a PR, then remove this hack
-        const networkIdIfExists = await this._web3Wrapper.getNetworkIdIfExistsAsync();
-        const gas = networkIdIfExists === constants.TESTRPC_NETWORK_ID ? ALLOWANCE_TO_ZERO_GAS_AMOUNT : undefined;
-        const txHash = await tokenContract.approve.sendTransactionAsync(spenderAddress, amountInBaseUnits, {
-            from: ownerAddress,
-            gas,
-        });
-        return txHash;
-    }
-    /**
-     * Sets the spender's allowance to an unlimited number of baseUnits on behalf of the owner address.
-     * Equivalent to the ERC20 spec method `approve`.
-     * Setting an unlimited allowance will lower the gas cost for filling orders involving tokens that forego updating
-     * allowances set to the max amount (e.g ZRX, WETH)
-     * @param   tokenAddress        The hex encoded contract Ethereum address where the ERC20 token is deployed.
-     * @param   ownerAddress        The hex encoded user Ethereum address who would like to set an allowance
-     *                              for spenderAddress.
-     * @param   spenderAddress      The hex encoded user Ethereum address who will be able to spend the set allowance.
-     * @return Transaction hash.
-     */
-    public async setUnlimitedAllowanceAsync(tokenAddress: string, ownerAddress: string,
-                                            spenderAddress: string): Promise<string> {
-        const txHash = await this.setAllowanceAsync(
-            tokenAddress, ownerAddress, spenderAddress, this.UNLIMITED_ALLOWANCE_IN_BASE_UNITS,
-        );
-        return txHash;
-    }
-    /**
-     * Retrieves the owners allowance in baseUnits set to the spender's address.
-     * @param   tokenAddress    The hex encoded contract Ethereum address where the ERC20 token is deployed.
-     * @param   ownerAddress    The hex encoded user Ethereum address whose allowance to spenderAddress
-     *                          you would like to retrieve.
-     * @param   spenderAddress  The hex encoded user Ethereum address who can spend the allowance you are fetching.
-     * @param   methodOpts      Optional arguments this method accepts.
-     */
-    public async getAllowanceAsync(tokenAddress: string, ownerAddress: string,
-                                   spenderAddress: string, methodOpts?: MethodOpts): Promise<BigNumber> {
-        assert.isETHAddressHex('ownerAddress', ownerAddress);
-        assert.isETHAddressHex('tokenAddress', tokenAddress);
-
-        const tokenContract = await this._getTokenContractAsync(tokenAddress);
-        const defaultBlock = _.isUndefined(methodOpts) ? undefined : methodOpts.defaultBlock;
-        let allowanceInBaseUnits = await tokenContract.allowance.callAsync(ownerAddress, spenderAddress, defaultBlock);
-        // Wrap BigNumbers returned from web3 with our own (later) version of BigNumber
-        allowanceInBaseUnits = new BigNumber(allowanceInBaseUnits);
-        return allowanceInBaseUnits;
-    }
-    /**
-     * Retrieves the owner's allowance in baseUnits set to the 0x proxy contract.
-     * @param   tokenAddress    The hex encoded contract Ethereum address where the ERC20 token is deployed.
-     * @param   ownerAddress    The hex encoded user Ethereum address whose proxy contract allowance we are retrieving.
-     * @param   methodOpts      Optional arguments this method accepts.
-     */
-    public async getProxyAllowanceAsync(tokenAddress: string, ownerAddress: string,
-                                        methodOpts?: MethodOpts): Promise<BigNumber> {
-        assert.isETHAddressHex('ownerAddress', ownerAddress);
-        assert.isETHAddressHex('tokenAddress', tokenAddress);
-
-        const proxyAddress = await this._getTokenTransferProxyAddressAsync();
-        const allowanceInBaseUnits = await this.getAllowanceAsync(tokenAddress, ownerAddress, proxyAddress, methodOpts);
-        return allowanceInBaseUnits;
-    }
-    /**
-     * Sets the 0x proxy contract's allowance to a specified number of a tokens' baseUnits on behalf
-     * of an owner address.
-     * @param   tokenAddress        The hex encoded contract Ethereum address where the ERC20 token is deployed.
-     * @param   ownerAddress        The hex encoded user Ethereum address who is setting an allowance
-     *                              for the Proxy contract.
-     * @param   amountInBaseUnits   The allowance amount specified in baseUnits.
-     * @return Transaction hash.
-     */
-    public async setProxyAllowanceAsync(tokenAddress: string, ownerAddress: string,
-                                        amountInBaseUnits: BigNumber): Promise<string> {
-        assert.isETHAddressHex('ownerAddress', ownerAddress);
-        assert.isETHAddressHex('tokenAddress', tokenAddress);
-        assert.isValidBaseUnitAmount('amountInBaseUnits', amountInBaseUnits);
-
-        const proxyAddress = await this._getTokenTransferProxyAddressAsync();
-        const txHash = await this.setAllowanceAsync(tokenAddress, ownerAddress, proxyAddress, amountInBaseUnits);
-        return txHash;
-    }
-    /**
-     * Sets the 0x proxy contract's allowance to a unlimited number of a tokens' baseUnits on behalf
-     * of an owner address.
-     * Setting an unlimited allowance will lower the gas cost for filling orders involving tokens that forego updating
-     * allowances set to the max amount (e.g ZRX, WETH)
-     * @param   tokenAddress        The hex encoded contract Ethereum address where the ERC20 token is deployed.
-     * @param   ownerAddress        The hex encoded user Ethereum address who is setting an allowance
-     *                              for the Proxy contract.
-     * @return Transaction hash.
-     */
-    public async setUnlimitedProxyAllowanceAsync(tokenAddress: string, ownerAddress: string): Promise<string> {
-        const txHash = await this.setProxyAllowanceAsync(
-            tokenAddress, ownerAddress, this.UNLIMITED_ALLOWANCE_IN_BASE_UNITS,
-        );
-        return txHash;
-    }
-    /**
-     * Transfers `amountInBaseUnits` ERC20 tokens from `fromAddress` to `toAddress`.
-     * @param   tokenAddress        The hex encoded contract Ethereum address where the ERC20 token is deployed.
-     * @param   fromAddress         The hex encoded user Ethereum address that will send the funds.
-     * @param   toAddress           The hex encoded user Ethereum address that will receive the funds.
-     * @param   amountInBaseUnits   The amount (specified in baseUnits) of the token to transfer.
-     * @return Transaction hash.
-     */
-    public async transferAsync(tokenAddress: string, fromAddress: string, toAddress: string,
-                               amountInBaseUnits: BigNumber): Promise<string> {
-        assert.isETHAddressHex('tokenAddress', tokenAddress);
-        await assert.isSenderAddressAsync('fromAddress', fromAddress, this._web3Wrapper);
-        assert.isETHAddressHex('toAddress', toAddress);
-        assert.isValidBaseUnitAmount('amountInBaseUnits', amountInBaseUnits);
-
-        const tokenContract = await this._getTokenContractAsync(tokenAddress);
-
-        const fromAddressBalance = await this.getBalanceAsync(tokenAddress, fromAddress);
-        if (fromAddressBalance.lessThan(amountInBaseUnits)) {
-            throw new Error(ZeroExError.InsufficientBalanceForTransfer);
-        }
-
-        const txHash = await tokenContract.transfer.sendTransactionAsync(toAddress, amountInBaseUnits, {
-            from: fromAddress,
-        });
-        return txHash;
-    }
-    /**
-     * Transfers `amountInBaseUnits` ERC20 tokens from `fromAddress` to `toAddress`.
-     * Requires the fromAddress to have sufficient funds and to have approved an allowance of
-     * `amountInBaseUnits` to `senderAddress`.
-     * @param   tokenAddress        The hex encoded contract Ethereum address where the ERC20 token is deployed.
-     * @param   fromAddress         The hex encoded user Ethereum address whose funds are being sent.
-     * @param   toAddress           The hex encoded user Ethereum address that will receive the funds.
-     * @param   senderAddress       The hex encoded user Ethereum address whose initiates the fund transfer. The
-     *                              `fromAddress` must have set an allowance to the `senderAddress`
-     *                              before this call.
-     * @param   amountInBaseUnits   The amount (specified in baseUnits) of the token to transfer.
-     * @return Transaction hash.
-     */
-    public async transferFromAsync(tokenAddress: string, fromAddress: string, toAddress: string,
-                                   senderAddress: string, amountInBaseUnits: BigNumber):
-                                   Promise<string> {
-        assert.isETHAddressHex('tokenAddress', tokenAddress);
-        assert.isETHAddressHex('fromAddress', fromAddress);
-        assert.isETHAddressHex('toAddress', toAddress);
-        await assert.isSenderAddressAsync('senderAddress', senderAddress, this._web3Wrapper);
-        assert.isValidBaseUnitAmount('amountInBaseUnits', amountInBaseUnits);
-
-        const tokenContract = await this._getTokenContractAsync(tokenAddress);
-
-        const fromAddressAllowance = await this.getAllowanceAsync(tokenAddress, fromAddress, senderAddress);
-        if (fromAddressAllowance.lessThan(amountInBaseUnits)) {
-            throw new Error(ZeroExError.InsufficientAllowanceForTransfer);
-        }
-
-        const fromAddressBalance = await this.getBalanceAsync(tokenAddress, fromAddress);
-        if (fromAddressBalance.lessThan(amountInBaseUnits)) {
-            throw new Error(ZeroExError.InsufficientBalanceForTransfer);
-        }
-
-        const txHash = await tokenContract.transferFrom.sendTransactionAsync(
-            fromAddress, toAddress, amountInBaseUnits,
-            {
-                from: senderAddress,
-            },
-        );
-        return txHash;
-    }
-    /**
-     * Subscribe to an event type emitted by the Token contract.
-     * @param   tokenAddress        The hex encoded address where the ERC20 token is deployed.
-     * @param   eventName           The token contract event you would like to subscribe to.
-     * @param   indexFilterValues   An object where the keys are indexed args returned by the event and
-     *                              the value is the value you are interested in. E.g `{maker: aUserAddressHex}`
-     * @param   callback            Callback that gets called when a log is added/removed
-     * @return Subscription token used later to unsubscribe
-     */
-    public subscribe<ArgsType extends TokenContractEventArgs>(
-        tokenAddress: string, eventName: TokenEvents, indexFilterValues: IndexedFilterValues,
-        callback: EventCallback<ArgsType>): string {
-        assert.isETHAddressHex('tokenAddress', tokenAddress);
-        assert.doesBelongToStringEnum('eventName', eventName, TokenEvents);
-        assert.doesConformToSchema('indexFilterValues', indexFilterValues, schemas.indexFilterValuesSchema);
-        assert.isFunction('callback', callback);
-        const subscriptionToken = this._subscribe<ArgsType>(
-            tokenAddress, eventName, indexFilterValues, artifacts.TokenArtifact.abi, callback,
-        );
-        return subscriptionToken;
-    }
-    /**
-     * Cancel a subscription
-     * @param   subscriptionToken Subscription token returned by `subscribe()`
-     */
-    public unsubscribe(subscriptionToken: string): void {
-        this._unsubscribe(subscriptionToken);
-    }
-    /**
-     * Gets historical logs without creating a subscription
-     * @param   tokenAddress        An address of the token that emmited the logs.
-     * @param   eventName           The token contract event you would like to subscribe to.
-     * @param   subscriptionOpts    Subscriptions options that let you configure the subscription.
-     * @param   indexFilterValues   An object where the keys are indexed args returned by the event and
-     *                              the value is the value you are interested in. E.g `{_from: aUserAddressHex}`
-     * @return  Array of logs that match the parameters
-     */
-    public async getLogsAsync<ArgsType extends TokenContractEventArgs>(
-        tokenAddress: string, eventName: TokenEvents, subscriptionOpts: SubscriptionOpts,
-        indexFilterValues: IndexedFilterValues): Promise<Array<LogWithDecodedArgs<ArgsType>>> {
-        assert.isETHAddressHex('tokenAddress', tokenAddress);
-        assert.doesBelongToStringEnum('eventName', eventName, TokenEvents);
-        assert.doesConformToSchema('subscriptionOpts', subscriptionOpts, schemas.subscriptionOptsSchema);
-        assert.doesConformToSchema('indexFilterValues', indexFilterValues, schemas.indexFilterValuesSchema);
-        const logs = await this._getLogsAsync<ArgsType>(
-            tokenAddress, eventName, subscriptionOpts, indexFilterValues, artifacts.TokenArtifact.abi,
-        );
-        return logs;
-    }
-    private _invalidateContractInstancesAsync(): void {
-        this.unsubscribeAll();
-        this._tokenContractsByAddress = {};
-    }
-    private async _getTokenContractAsync(tokenAddress: string): Promise<TokenContract> {
-        let tokenContract = this._tokenContractsByAddress[tokenAddress];
-        if (!_.isUndefined(tokenContract)) {
-            return tokenContract;
-        }
-        const contractInstance = await this._instantiateContractIfExistsAsync<TokenContract>(
-            artifacts.TokenArtifact, tokenAddress,
-        );
-        tokenContract = contractInstance as TokenContract;
-        this._tokenContractsByAddress[tokenAddress] = tokenContract;
-        return tokenContract;
-    }
-    private async _getTokenTransferProxyAddressAsync(): Promise<string> {
-        const tokenTransferProxyContractAddress = await this._tokenTransferProxyContractAddressFetcher();
-        return tokenTransferProxyContractAddress;
-    }
-}