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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 decode(self, dataset_split=None, decode_from_file=False, checkpoint_path=None):
 """Decodes from dataset or file."""

    if decode_from_file:
      decoding.decode_from_file(self._estimator,
                                self._decode_hparams.decode_from_file,
                                self._hparams,
                                self._decode_hparams,
                                self._decode_hparams.decode_to_file)
    else:
      decoding.decode_from_dataset(
          self._estimator,
          self._hparams.problem.name,
          self._hparams,
          self._decode_hparams,
          dataset_split=dataset_split,
          checkpoint_path=checkpoint_path)