class_docstr: Problem spec for WMT En-Zh translation.
  
  This is far from being the real WMT17 task - only toyset here
docstr: Uses only News Commentary Dataset for training.
docstr_tok: ["Uses","only","News","Commentary","Dataset","for","training","."]
code: def get_training_dataset(self, tmp_dir):
      """Uses only News Commentary Dataset for training."""
      return _NC_TRAIN_DATASETS
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  from tensor2tensor.data_generators import generator_utils
  from tensor2tensor.data_generators import problem
  from tensor2tensor.data_generators import text_encoder
  from tensor2tensor.data_generators import text_problems
  from tensor2tensor.data_generators import translate
  from tensor2tensor.utils import registry
  import tensorflow.compat.v1
label_desc: Use image node_id 3 for calling the TranslateEnzhWmt8k obj's underlying member method code with example usage: obj.get_training_dataset(tmp_dir) and returns: _NC_TRAIN_DATASETS