code: def all_corpus_files(data_prefix):
      return sorted(tf.gfile.Glob(data_prefix + "*"))
  
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 18 for calling a global function with example usage: all_corpus_files(data_prefix) and returns: sorted