'Return links (iterator)
withKeys: return link keys
withInfo: return link info
returns: list of ( src, dst [,key, info ] )'

def iterLinks(self, withKeys=False, withInfo=False):

    for (_src, _dst, key, info) in self.g.edges_iter(data=True, keys=True):
        (node1, node2) = (info['node1'], info['node2'])
        if withKeys:
            if withInfo:
                (yield (node1, node2, key, info))
            else:
                (yield (node1, node2, key))
        elif withInfo:
            (yield (node1, node2, info))
        else:
            (yield (node1, node2))
