class_docstr: Corpus of Linguistic Acceptability classification problems.
code: def _maybe_download_corpora(self, tmp_dir):
      cola_filename = "CoLA.zip"
      cola_finalpath = os.path.join(tmp_dir, "CoLA")
      if not tf.gfile.Exists(cola_finalpath):
          zip_filepath = generator_utils.maybe_download(
              tmp_dir, cola_filename, self._COLA_URL
          )
          zip_ref = zipfile.ZipFile(zip_filepath, "r")
          zip_ref.extractall(tmp_dir)
          zip_ref.close()
  
      return cola_finalpath
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  import zipfile
  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.utils import registry
  import tensorflow.compat.v1
label_desc: Use image node_id 6 for calling the Cola obj's underlying member method code with example usage: obj._maybe_download_corpora(tmp_dir) and returns: cola_finalpath