code: def test_unweighted(self):
      self.setup()
      cosine_obj = metrics.CosineSimilarity()
      loss = cosine_obj(self.y_true, self.y_pred)
      expected_loss = np.mean(self.expected_loss)
      self.assertAlmostEqual(loss, expected_loss, 3)
  
imports: import numpy
  from absl.testing import parameterized
  from keras import testing
  from keras.metrics import regression_metrics
label_desc: Use image node_id 4 for calling the CosineSimilarityTest obj's underlying member method code with example usage: obj.test_unweighted() without return types