[vtkusers] Disallow multiple graph edges?

[David Doria]

Is there anything in place to prevent adding the same edge twice? That
is, if I do this:

vtkMutableUndirectedGraph* G = vtkMutableUndirectedGraph::New();
  vtkIdType V1 = G->AddVertex();
  vtkIdType V2 = G->AddVertex();
  G->AddEdge ( V1, V2 );
  G->AddEdge ( V1, V2 );

There will now be two edges between V1 and V2. Some algorithms do not
allow this. Is there a flag anywhere to disallow these duplicate
edges? Or would I have to get all the edges of V1 and check if any of
their Destinations are V2 manually every time before adding an edge?

Thanks,

David