code: def advance_for_next_slice(self, recovery_slice=False):
      
      self.slice_start_time = None
      self.slice_request_id = None
      self.slice_retries = 0
      self.acquired_once = False
      if recovery_slice:
        self.slice_id += 2
      else:
        self.slice_id += 1
docs: Advance self for next slice.
  
      Args:
        recovery_slice: True if this slice is running recovery logic.
          See handlers.MapperWorkerCallbackHandler._attempt_slice_recovery
          for more info.