code: def do_execute(self):
          
          relname = self.resolve_option("name")
          if isinstance(self.input.payload, Instance):
              self.input.payload.dataset.relationname = relname
          else:
              self.input.payload.relationname = relname
          self._output.append(self.input)
          return None
docs: The actual execution of the actor.
  
          :return: None if successful, otherwise error message
          :rtype: str