class_docstr: CMVN unittest Class
code: def setUp(self):
      super().setUp()
      """ setup """
  
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 1 for calling the CmvnTest obj's underlying member method code with example usage: obj.setUp() without return types