class_docstr: Base class for Wikisum problems.
class_docstr_tok: ["Base","class","for","Wikisum","problems","."]
code: def vocab_filename(self):
      return "vocab.%s.%d" % (
          self.dataset_filename(),
          self.target_vocab_size,
      )
  
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 3 for calling the WikisumBase obj's underlying member method code with example usage: obj.vocab_filename() and returns: unknown