code: def _story_summary_split(story):
      split_str = " <summary> "
      split_str_len = len(split_str)
      split_pos = story.find(split_str)
      return story[:split_pos], story[split_pos + split_str_len :]
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import hashlib
  import io
  import os
  import random
  import tarfile
  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 wiki_lm
  from tensor2tensor.utils import registry
  import tensorflow.compat.v1
label_desc: Use image node_id 4 for calling a global function with example usage: _story_summary_split(story) and returns: story,  story