accounts, consensus, core, eth: make chain maker consensus agnostic (#15497)

* accounts, consensus, core, eth: make chain maker consensus agnostic

* consensus, core: move CalcDifficulty to Engine interface

* consensus: add docs for calcDifficulty function

* consensus, core: minor comment fixups

1 files changed, 1 insertions, 1 deletions

diff --git a/eth/handler_test.go b/eth/handler_test.go
index 6752cd2a8..ebbd83c3a 100644
--- a/eth/handler_test.go
+++ b/eth/handler_test.go
@@ -498,7 +498,7 @@ func testDAOChallenge(t *testing.T, localForked, remoteForked bool, timeout bool
 	}
 	// Create a block to reply to the challenge if no timeout is simulated
 	if !timeout {
-		blocks, _ := core.GenerateChain(&params.ChainConfig{}, genesis, db, 1, func(i int, block *core.BlockGen) {
+		blocks, _ := core.GenerateChain(&params.ChainConfig{}, genesis, ethash.NewFaker(), db, 1, func(i int, block *core.BlockGen) {
 			if remoteForked {
 				block.SetExtra(params.DAOForkBlockExtra)
 			}