class_docstr: Toy model to test mesh_tensorflow.
class_docstr_tok: ["Toy","model","to","test","mesh_tensorflow","."]
code: def mtf_model_fn(self, features, mesh):
      raise NotImplementedError("Not implemented")
  
file_path: tensor2tensor/tensor2tensor/utils/mtf_model.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import mesh_tensorflow
  import six
  from tensor2tensor.utils import hparams_lib
  from tensor2tensor.utils import learning_rate
  from tensor2tensor.utils import metrics
  from tensor2tensor.utils import t2t_model
  import tensorflow.compat.v1
  from tensorflow.compat.v1 import estimator
  from tensorflow.contrib.tpu.python.tpu import tpu_estimator
label_desc: Use image node_id 5 for calling the MtfModel obj's underlying member method code with example usage: obj.mtf_model_fn(features, mesh) without return types