class_docstr: Problem to train on full 960h, but evaluate on clean data only.
code: def dev_filepaths(self, data_dir, num_shards, shuffled):
      return LibrispeechClean.dev_filepaths(
          self, data_dir, num_shards, shuffled
      )
  
imports: import os
  import tarfile
  from tensor2tensor.data_generators import generator_utils
  from tensor2tensor.data_generators import problem
  from tensor2tensor.data_generators import speech_recognition
  from tensor2tensor.utils import registry
  from tensorflow.compat.v1 import estimator
label_desc: Use image node_id 2 for calling the LibrispeechTrainFullTestClean obj's underlying member method code with example usage: obj.dev_filepaths(data_dir, num_shards, shuffled) and returns: LibrispeechClean