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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 _attempt_slice_retry(self, shard_state, tstate):
 """Attempt to retry this slice. This method may modify shard_state and tstate to prepare for retry or fail. Args: shard_state: model.ShardState for current shard. tstate: model.TransientShardState for current shard. Returns: A _TASK_DIRECTIVE enum. RETRY_SLICE if slice should be retried. RETRY_SHARD if shard retry should be attempted. """

    if (shard_state.slice_retries + 1 <
        parameters.config.TASK_MAX_DATA_PROCESSING_ATTEMPTS):
      logging.warning(
          "Slice %s %s failed for the %s of up to %s attempts "
          "(%s of %s taskqueue execution attempts). "
          "Will retry now.",
          tstate.shard_id,
          tstate.slice_id,
          shard_state.slice_retries + 1,
          parameters.config.TASK_MAX_DATA_PROCESSING_ATTEMPTS,
          self.task_retry_count() + 1,
          parameters.config.TASK_MAX_ATTEMPTS)
      # Clear info related to current exception. Otherwise, the real
      # callstack that includes a frame for this method will show up
      # in log.
      sys.exc_clear()
      self._try_free_lease(shard_state, slice_retry=True)
      return self._TASK_DIRECTIVE.RETRY_SLICE

    if parameters.config.TASK_MAX_DATA_PROCESSING_ATTEMPTS > 0:
      logging.warning("Slice attempt %s exceeded %s max attempts.",
                      self.task_retry_count() + 1,
                      parameters.config.TASK_MAX_DATA_PROCESSING_ATTEMPTS)
    return self._TASK_DIRECTIVE.RETRY_SHARD