def __init__(self, graphs, store='default'):
        if store is not None:
            super(ReadOnlyGraphAggregate, self).__init__(store)
            Graph.__init__(self, store)
            self.__namespace_manager = None

        assert isinstance(graphs, list) \
            or graphs \
            and [g for g in graphs if isinstance(g, Graph)], \
            "graphs argument must be a list of Graphs!!"
        self.graphs = graphs
dataset/ETHPy150Open RDFLib/rdflib/rdflib/graph.py/ReadOnlyGraphAggregate.__init__/operator `and` -> `or`