Export graph to dot util

Change-Id: I385a469a15ae3afcc260cc0be3a0971952ca5e8d
Boot fake vm example fixed

Change-Id: I4e4b3074866b638b6ab2817994533a0f255e5c28
Remove old tests for unexisted flow types

Change-Id: Iadb491185748199dcdff9f6ef8df73bcd862cb1d
Merge "Export graph to dot util"
Merge "Boot fake vm example fixed"
Merge "Remove old tests for unexisted flow types"