class_docstr: Packed version, 8k vocabulary.
  
  Ratio of dev tokens (including eos) to dev words (including eos)
  207351 / 159658 = 1.29872; multiply log-ppl by this to compare results.
class_docstr_tok: ["Packed","version",",","8k","vocabulary",".","Ratio","of","dev","tokens","(","including","eos",")","to","dev","words","(","including","eos",")","207351","\/","159658","=","1.29872",";","multiply","log-ppl","by","this","to","compare","results","."]
code: def vocab_filename(self):
      return LanguagemodelLm1b8k().vocab_filename
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  import tarfile
  from six.moves import range
  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.utils import registry
  import tensorflow.compat.v1
label_desc: Use image node_id 2 for calling the LanguagemodelLm1b8kPacked obj's underlying member method code with example usage: obj.vocab_filename() and returns: LanguagemodelLm1b8k