class_docstr: Base class for CoNLL2002 problems.
class_docstr_tok: ["Base","class","for","CoNLL2002","problems","."]
docstr: Files to be passed to generate_samples.
docstr_tok: ["Files","to","be","passed","to","generate_samples","."]
code: def source_data_files(self, dataset_split):
      """Files to be passed to generate_samples."""
      raise NotImplementedError()
  
file_path: tensor2tensor/tensor2tensor/data_generators/conll_ner.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  import zipfile
  from tensor2tensor.data_generators import generator_utils
  from tensor2tensor.data_generators import problem
  from tensor2tensor.data_generators import text_problems
  from tensor2tensor.utils import registry
  import tensorflow.compat.v1
label_desc: Use image node_id 1 for calling the Conll2002Ner obj's underlying member method code with example usage: obj.source_data_files(dataset_split) without return types