We use strategies as constraints for object collaborations. 

Aspectual collaborations also have an interface class graph
but the behavior is not necessarily expressed in terms of adaptive methods.
In addition we have aspectual methods. What are the constraints
for aspectual collaborations?
One node may be mapped to many other nodes.
One node may be mapped to only one other node.

The mapped nodes must satisfy certain properties like they 
must have certain methods with certain properties.
Property constrains execution history paths or paths.

cflow of method call must satisfy certain properties.
execution trace of method call must satisfy certain properties.



A visitor can be viewed as an aspectual collaboration.
Connection is given by strategies/interface class graph.