def get_entity(self, uri: str) -> OntologyClass:
        """
        Find an ontology entity based on URI

        :param uri: URIRef or str
        :return: the OntologyEntity having the specified uri, or None
        """
        return self.entities.get(str(uri), None)
Find an ontology entity based on URI

        :param uri: URIRef or str
        :return: the OntologyEntity having the specified uri, or None