code: def example_generator(all_files, urls_path, sum_token):
    
  
    def fix_run_on_sents(line):
      if u"@highlight" in line:
        return line
      if not line:
        return line
      if line[-1] in END_TOKENS:
        return line
      return line + u"."
  
    filelist = example_splits(urls_path, all_files)
    story_summary_split_token = u" <summary> " if sum_token else " "
  
    for story_file in filelist:
      story = []
      summary = []
      reading_highlights = False
      for line in tf.gfile.Open(story_file, "rb"):
        line = text_encoder.to_unicode_utf8(line.strip())
        line = fix_run_on_sents(line)
        if not line:
          continue
        elif line.startswith(u"@highlight"):
          if not story:
            break  # No article text.
          reading_highlights = True
        elif reading_highlights:
          summary.append(line)
        else:
          story.append(line)
  
      if (not story) or not summary:
        continue
  
      yield " ".join(story) + story_summary_split_token + " ".join(summary)
docs: Generate examples.