def _spoc(self, triple_or_quad, default=False):
        """
        helper method for having methods that support
        either triples or quads
        """
        if triple_or_quad <= None:
            return (None, None, None, self.default_context if default else None)
        if len(triple_or_quad) == 3:
            c = self.default_context if default else None
            (s, p, o) = triple_or_quad
        elif len(triple_or_quad) == 4:
            (s, p, o, c) = triple_or_quad
            c = self._graph(c)
        return s,p,o,c
dataset/ETHPy150Open RDFLib/rdflib/rdflib/graph.py/ConjunctiveGraph._spoc/operator `is` -> `<=`