Expose some way to get the individual nodes of the CFG

Needed for debugging/checking purposes since there is no other way to
easily retrieve a value from the Dataflow system other than by querying
data for a node in the CFG.

See #2.
Expose some way to get the individual nodes of the CFG

Needed for debugging/checking purposes since there is no other way to
easily retrieve a value from the Dataflow system other than by querying
data for a node in the CFG.

See #2.