code: def setup(self):
          
          result = super(ActorHandler, self).setup()
          if result is None:
              self.update_parent()
              try:
                  self.check_actors(self.actors)
              except Exception as e:
                  result = str(e)
          if result is None:
              for actor in self.actors:
                  name = actor.name
                  newname = actor.unique_name(actor.name)
                  if name != newname:
                      actor.name = newname
          if result is None:
              for actor in self.actors:
                  if actor.skip:
                      continue
                  result = actor.setup()
                  if result is not None:
                      break
          if result is None:
              result = self._director.setup()
          return result
docs: Configures the actor before execution.
  
          :return: None if successful, otherwise error message
          :rtype: str