code: def _inherit_outputs(self,
                         pipeline_name,
                         already_defined,
                         resolve_outputs=False):
      
      for name, slot_key in already_defined.iteritems():
        if not isinstance(slot_key, db.Key):
          slot_key = db.Key(slot_key)
  
        slot = self._output_dict.get(name)
        if slot is None:
          if self._strict:
            raise UnexpectedPipelineError(
                'Inherited output named "%s" must be filled but '
                'not declared for pipeline class "%s"' % (name, pipeline_name))
          else:
            self._output_dict[name] = Slot(name=name, slot_key=slot_key)
        else:
          slot.key = slot_key
          slot._exists = True
  
      if resolve_outputs:
        slot_key_dict = dict((s.key, s) for s in self._output_dict.itervalues())
        all_slots = db.get(slot_key_dict.keys())
        for slot, slot_record in zip(slot_key_dict.itervalues(), all_slots):
          if slot_record is None:
            raise UnexpectedPipelineError(
                'Inherited output named "%s" for pipeline class "%s" is '
                'missing its Slot in the datastore: "%s"' %
                (slot.name, pipeline_name, slot.key))
          slot = slot_key_dict[slot_record.key()]
          slot._set_value(slot_record)
docs: Inherits outputs from a calling Pipeline.
  
      Args:
        pipeline_name: The Pipeline class name (used for debugging).
        already_defined: Maps output name to stringified db.Key (of _SlotRecords)
          of any exiting output slots to be inherited by this future.
        resolve_outputs: When True, this method will dereference all output slots
          before returning back to the caller, making those output slots' values
          available.
  
      Raises:
        UnexpectedPipelineError when resolve_outputs is True and any of the output
        slots could not be retrived from the Datastore.