def relationship(self, id_):
        """ Fetch a relationship by ID.

        :param id_:
        """
        resource = remote(self).resolve("relationship/" + str(id_))
        uri_string = resource.uri.string
        try:
            return Relationship.cache[uri_string]
        except __HOLE__:
            relationship = self.evaluate("MATCH ()-[r]->() WHERE id(r)={x} RETURN r", x=id_)
            if relationship is None:
                raise IndexError("Relationship %d not found" % id_)
            else:
                return relationship
dataset/ETHPy150Open nigelsmall/py2neo/py2neo/database/__init__.py/Graph.relationship