code: def test_rmse_loss_value(self):
      with self.cached_session():
          predicted = tf.constant(
              [[1.2, 1]], dtype=tf.float32, name="predicted"
          )
          labels = tf.constant(
              [[1, 0]], dtype=tf.float32, name="labels"
          )
          test_loss_func = LossFunction(loss_type="RMSE")
          computed_rmse_loss = test_loss_func(predicted, labels)
          self.assertAlmostEqual(
              computed_rmse_loss.eval(), 0.7211, places=4
          )
  
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 1 for calling the RMSELossTests obj's underlying member method code with example usage: obj.test_rmse_loss_value() without return types