def testConstants(self):
        self.assertIsInstance(NSMetadataQueryDidStartGatheringNotification, unicode)
        self.assertIsInstance(NSMetadataQueryGatheringProgressNotification, unicode)
        self.assertIsInstance(NSMetadataQueryDidFinishGatheringNotification, unicode)
        self.assertIsInstance(NSMetadataQueryDidUpdateNotification, unicode)
        self.assertIsInstance(NSMetadataQueryResultContentRelevanceAttribute, unicode)
        self.assertIsInstance(NSMetadataQueryUserHomeScope, unicode)
        self.assertIsInstance(NSMetadataQueryLocalComputerScope, unicode)
        self.assertIsInstance(NSMetadataQueryNetworkScope, unicode)