core: add shard (#127)

A shard is basically DEXON v1 components,
except the strongly acked part, including:
- maintaining lattice structure
- total ordering
- generate consensus timestamp

1 files changed, 7 insertions, 2 deletions

diff --git a/core/test/governance.go b/core/test/governance.go
index a2e6f69..63462d0 100644
--- a/core/test/governance.go
+++ b/core/test/governance.go
@@ -65,8 +65,13 @@ func NewGovernance(nodeCount int, lambda time.Duration) (
 
 // GetNotarySet implements Governance interface to return current
 // notary set.
-func (g *Governance) GetNotarySet() map[types.NodeID]struct{} {
-	return g.notarySet
+func (g *Governance) GetNotarySet() (ret map[types.NodeID]struct{}) {
+	// Return a cloned map.
+	ret = make(map[types.NodeID]struct{})
+	for k := range g.notarySet {
+		ret[k] = struct{}{}
+	}
+	return
 }
 
 // GetConfiguration returns the configuration at a given block height.