def __str__(self):
        """Return graph in adjacency format.

        >>> g = Graph()
        >>> g.add(range(3), range(3))
        >>> str(g)
        '{0: {0, 1, 2}, 1: {0, 1, 2}, 2: {0, 1, 2}}'
        >>> g = Graph(VertexType=WVertex)
        >>> g.add(range(3), range(3))
        >>> str(g)
        '{0: {0: 1, 1: 1, 2: 1}, 1: {0: 1, 1: 1, 2: 1}, 2: {0: 1, 1: 1, 2: 1}}'
        """
        if _DEBUG: self._validate()
        return super(Graph, self).__str__()
        #return '{%s}' % ', '.join(map(str, self.itervalues()))
Return graph in adjacency format.

        >>> g = Graph()
        >>> g.add(range(3), range(3))
        >>> str(g)
        '{0: {0, 1, 2}, 1: {0, 1, 2}, 2: {0, 1, 2}}'
        >>> g = Graph(VertexType=WVertex)
        >>> g.add(range(3), range(3))
        >>> str(g)
        '{0: {0: 1, 1: 1, 2: 1}, 1: {0: 1, 1: 1, 2: 1}, 2: {0: 1, 1: 1, 2: 1}}'
        
recipes/Python/578615_graph/recipe-578615.py