(self, other)
return NotImplemented
Coercion rules.

        This method is needed to allow the graph to react to additions
        with lists, tuples, integers, strings, vertices, edges and so on.
Coercion rules.
Coercion rules .
def __coerce__(self, other):
        """Coercion rules.

        This method is needed to allow the graph to react to additions
        with lists, tuples, integers, strings, vertices, edges and so on.
        """
        if isinstance(other, (int, tuple, list, str)):
            return self, other
        if isinstance(other, Vertex):
            return self, other
        if isinstance(other, VertexSeq):
            return self, other
        if isinstance(other, Edge):
            return self, other
        if isinstance(other, EdgeSeq):
            return self, other
        return NotImplemented
def __coerce__ ( self , other ) : if isinstance ( other , ( int , tuple , list , str ) ) : return self , other if isinstance ( other , Vertex ) : return self , other if isinstance ( other , VertexSeq ) : return self , other if isinstance ( other , Edge ) : return self , other if isinstance ( other , EdgeSeq ) : return self , other return NotImplemented