def testSymmetry(self):
        '''Check that distance is symmetric.'''

        model = word2vec.Word2Vec(sentences, min_count=2, seed=42, workers=1)
        sentence1 = ['human', 'interface', 'computer']
        sentence2 = ['survey', 'user', 'computer', 'system', 'response', 'time']
        distance1 = model.wv.wmdistance(sentence1, sentence2)
        distance2 = model.wv.wmdistance(sentence2, sentence1)
        self.assertTrue(np.allclose(distance1, distance2))