code: def _assign_uid(self, sid):
          
          self._uid = ru.generate_id(
              'pipeline.%(item_counter)04d', ru.ID_CUSTOM, namespace=sid)
          for stage in self._stages:
              stage._assign_uid(sid)
  
          self._pass_uid()
docs: Purpose: Assign a uid to the current object based on the sid passed. Pass the current uid to children of
          current object