class_docstr: Problem spec for WMT En-Zh translation.
  
  Attempts to use full training dataset, which needs website
  registration and downloaded manually from official sources:
  
  CWMT:
    - http://nlp.nju.edu.cn/cwmt-wmt/
    - Website contains instructions for FTP server access.
    - You'll need to download CASIA, CASICT, DATUM2015, DATUM2017,
        NEU datasets
  
  UN Parallel Corpus:
    - https://conferences.unite.un.org/UNCorpus
    - You'll need to register your to download the dataset.
  
  NOTE: place into tmp directory e.g. /tmp/t2t_datagen/dataset.tgz
docstr: UN Parallel Corpus and CWMT Corpus need to be downloaded manually.
  
  Append to training dataset if available
  
  Args:
    tmp_dir: path to temporary dir with the data in it.
  
  Returns:
    paths
docstr_tok: ["UN","Parallel","Corpus","and","CWMT","Corpus","need","to","be","downloaded","manually",".","Append","to","training","dataset","if","available","Args",":","tmp_dir",":","path","to","temporary","dir","with","the","data","in","it",".","Returns",":","paths"]
code: def get_training_dataset(self, tmp_dir):
      """UN Parallel Corpus and CWMT Corpus need to be downloaded manually.
  
      Append to training dataset if available
  
      Args:
        tmp_dir: path to temporary dir with the data in it.
  
      Returns:
        paths
      """
      full_dataset = _NC_TRAIN_DATASETS
      for dataset in [_CWMT_TRAIN_DATASETS, _UN_TRAIN_DATASETS]:
          filename = get_filename(dataset)
          tmp_filepath = os.path.join(tmp_dir, filename)
          if tf.gfile.Exists(tmp_filepath):
              full_dataset += dataset
          else:
              tf.logging.info(
                  "[TranslateEzhWmt] dataset incomplete, you need to "
                  "manually download %s" % filename
              )
      return full_dataset
  
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 4 for calling the TranslateEnzhWmt32k obj's underlying member method code with example usage: obj.get_training_dataset(tmp_dir) and returns: full_dataset