code: def test_cosine_loss_value_equal(self):
      with self.cached_session():
          predicted = tf.constant(
              [[[0.5, 0.5]]], dtype=tf.float32, name="predicted"
          )
          labels = tf.constant(
              [[[0.5, 0.5]]], dtype=tf.float32, name="labels"
          )
          test_loss_func = LossFunction(loss_type="Cosine")
          computed_cosine_loss = test_loss_func(predicted, labels)
          self.assertAlmostEqual(computed_cosine_loss.eval(), 0)
  
imports: from __future__ import absolute_import, print_function
  import tensorflow
  from niftynet.layer.loss_regression import LossFunction
  from niftynet.layer.loss_regression import l1_loss, l2_loss, huber_loss, smooth_l1_loss, cosine_loss
  from tests.niftynet_testcase import NiftyNetTestCase
label_desc: Use image node_id 2 for calling the CosineLossTests obj's underlying member method code with example usage: obj.test_cosine_loss_value_equal() without return types