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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def transformer_librispeech_tpu_v2():
 """HParams for training ASR model on Librispeech on TPU v2."""

  hparams = transformer_librispeech_v2()
  update_hparams_for_tpu(hparams)

  hparams.batch_size = 16
  librispeech.set_librispeech_length_hparams(hparams)
  return hparams