def __str__(self):
        if isinstance(self.identifier, URIRef):
            return (
                "%s a rdfg:Graph;rdflib:storage " + "[a rdflib:Store;rdfs:label '%s']."
            ) % (self.identifier.n3(), self.store.__class__.__name__)
        else:
            return (
                "[a rdfg:Graph;rdflib:storage " + "[a rdflib:Store;rdfs:label '%s']]."
            ) % self.store.__class__.__name__