def quads(self, (s, p, o)):
        for graph in self.graphs:
            for s1, p1, o1 in graph.triples((s, p, o)):
                yield (s1, p1, o1, graph)
Iterate over all the quads in the entire aggregate graph
dataset/ETHPy150Open RDFLib/rdflib/rdflib/graph.py/ReadOnlyGraphAggregate.quads