class_docstr: CMVN unittest Class
docstr: test load cmvn 
docstr_tok: ["test","load","cmvn"]
code: def testLoadCmvn(self):  # pylint: disable=invalid-name
      """test load cmvn"""
      np.random.seed(12)
      temp_dir = self.get_temp_dir()
      temp_file = os.path.join(temp_dir, "cmvn.npy")
  
      feat_size = 40
      delta_deltas = True
      shape = [1, feat_size, 3 if delta_deltas else 1]
      mean = np.random.randn(*shape)
      var = np.random.randn(*shape)
      mean, var = mean.astype(np.float32), var.astype(np.float32)
      with tf.gfile.Open(
          temp_file, "w"
      ) as f:  # pylint: disable=invalid-name
          np.save(f, (mean, var))
  
      mean_true = np.expand_dims(mean, axis=0)
      var_true = np.expand_dims(var, axis=0)
  
      with self.cached_session(use_gpu=False, force_gpu=False):
          mean, var = utils.load_cmvn(temp_file)
          self.assertAllClose(mean.eval(), mean_true)
          self.assertAllClose(var.eval(), var_true)
  
file_path: delta/delta/utils/cmvn_test.py
imports: import os
  import numpy
  import delta.compat
  from delta import utils
label_desc: Use image node_id 6 for calling the CmvnTest obj's underlying member method code with example usage: obj.testLoadCmvn() without return types