Validates if the edge passed in is addable to this graph structure. The start node and the end node for the are given as well. The same edge is present between startVertex and endVertex and also between endVertex and startVertex if the graph is a nondirected graph, hence the necessity of these two nodes in this routine

protected override bool ValidateEdgeForAddition(
	InheritanceEdge edgeToAdd,
	EntityDefinition startVertex,
	EntityDefinition endVertex
)

Protected Overrides Function ValidateEdgeForAddition ( 
	edgeToAdd As InheritanceEdge,
	startVertex As EntityDefinition,
	endVertex As EntityDefinition
) As Boolean