code: def _set_value(self, slot_record):
      
      if slot_record.status == _SlotRecord.FILLED:
        self.filled = True
        self._filler_pipeline_key = _SlotRecord.filler.get_value_for_datastore(
            slot_record)
        self._fill_datetime = slot_record.fill_time
        self._value = slot_record.value
docs: Sets the value of this slot based on its corresponding _SlotRecord.
  
      Does nothing if the slot has not yet been filled.
  
      Args:
        slot_record: The _SlotRecord containing this Slot's value.