code: def _encode_wiki_sections(sections, vocab):
      """Encodes sections with vocab. Returns ids and section boundaries."""
      ids = []
      section_boundaries = []
      for i, section in enumerate(sections):
          if i > 0:
              # Skip including article title
              ids.extend(
                  vocab.encode(
                      _format_title(_normalize_text(section.title))
                  )
              )
          ids.extend(vocab.encode(_normalize_text(section.text)))
          section_boundaries.append(len(ids))
  
      return ids, section_boundaries
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import collections
  import json
  import math
  import os
  import re
  import string
  import tempfile
  import six
  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 tokenizer
  from tensor2tensor.data_generators.wikisum import utils
  from tensor2tensor.layers import modalities
  from tensor2tensor.utils import metrics
  from tensor2tensor.utils import registry
  import tensorflow.compat.v1
label_desc: Use image node_id 15 for calling a global function with example usage: _encode_wiki_sections(sections, vocab) and returns: ids,  section_boundaries