def _check_analyze_entities_result(self, entities):
        from google.cloud.language.entity import EntityType
    
        self.assertEqual(len(entities), 3)
        entity1, entity2, entity3 = entities
        # Verify entity 1.
        self.assertEqual(entity1.name, self.NAME1)
        self.assertEqual(entity1.entity_type, EntityType.PERSON)
        self.assertGreater(entity1.salience, 0.0)
        # Other mentions may occur, e.g. "painter".
        self.assertIn(entity1.name, [str(i) for i in entity1.mentions])
>       self.assertEqual(entity1.metadata['wikipedia_url'],
                         'http://en.wikipedia.org/wiki/Caravaggio')
E       KeyError: 'wikipedia_url'