code: def testTxtLineIterator(self):
      lines = [
          line
          for line in text_problems.txt_line_iterator(self.inputs_file)
      ]
      self.assertEqual(lines, self.inputs)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  import shutil
  from tensor2tensor.data_generators import problem
  from tensor2tensor.data_generators import text_encoder
  from tensor2tensor.data_generators import text_problems
  import tensorflow.compat.v1
  from tensorflow.compat.v1 import estimator
label_desc: Use image node_id 2 for calling the TextProblems obj's underlying member method code with example usage: obj.testTxtLineIterator() without return types