Selection: Two Nodes in same graph.
Effect: The menu will provide an actions for every known reference between the types of the selected nodes. If one is chosen, an edge will be created with the selected type. The edges source and target will reference the two selected nodes.
The command checks for multiplicity and uniqueness of an edge. Therefore there may not be two equally-typed(and equally directed) edges between the two nodes. If a reference is not of a collection type(i.e. upperBound<2) there must not be an outgoing edge of the same type from the node whose class contains the reference.
Edges that may not be created for reasons of multiplicity or uniqueness violations are shown as disabled menu items.