code: def corpus_page_generator(corpus_files, tmp_dir, max_page_size_exp):
      """Generate pages from a list of .7z encoded history dumps.
  
      Args:
        corpus_files: a list of strings
        tmp_dir: a string
        max_page_size_exp: an integer
  
      Yields:
        strings
      """
      for remote_filepath in corpus_files:
          filepath = maybe_copy_file_to_directory(
              remote_filepath, tmp_dir
          )
          tf.logging.info("Reading from " + filepath)
  
          command = ["7z", "x", "-so", filepath]
          tf.logging.info("Running command: %s", command)
  
          p = subprocess.Popen(
              command, stdout=subprocess.PIPE, bufsize=-1
          )
  
          for page in file_page_generator(
              p.stdout, 2**max_page_size_exp
          ):
              yield page
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import math
  import os
  import random
  import re
  import subprocess
  from tensor2tensor.data_generators import generator_utils
  from tensor2tensor.data_generators import text_encoder
  import tensorflow.compat.v1
label_desc: Use image node_id 9 for calling a global function with example usage: corpus_page_generator(corpus_files, tmp_dir, max_page_size_exp) without return types