code: def testGlobalVarName(self):
      self.assertEqual(
          "x_(cake:lie)",
          layout_optimizer._global_var_name("cake", "lie"),
      )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import mesh_tensorflow
  from mesh_tensorflow.auto_mtf import layout_optimizer
  from mesh_tensorflow.auto_mtf import memory_estimator
  import six
  import tensorflow.compat.v1
label_desc: Use image node_id 1 for calling the VariableNamesTest obj's underlying member method code with example usage: obj.testGlobalVarName() without return types