code: def set_world(self, world):
          '''
          Sets the world an entity belongs to.
          Checks for tag conflicts before adding.
          '''
          if world.get_entity_by_tag(self._tag) and self._tag != '':
              raise NonUniqueTagError(self._tag)
          else:
              self._world = world
              world.add_entity(self, Truef set_world(self, world):
          '''
          Sets the world an entity belongs to.
          Checks for tag conflicts before adding.
          '''
          if world.get_entity_by_tag(self._tag) and self._tag != '':
              raise NonUniqueTagError(self._tag)
          else:
              self._world = world
              world.add_entity(self, True)
docs: Sets the world an entity belongs to.
          Checks for tag conflicts before adding.