docs: def update(self, time_delta):
          """Update all sprites in the system. time_delta is the
          time since the last update (in arbitrary time units).
  
          This method can be conveniently scheduled using the Pyglet
          scheduler method: pyglet.clock.schedule_interval
          """
          self.control.update(self, time_delta)
          for object in self.objects:
              object.update(time_delta)
              # object.sprite.last_position = object.sprite.position
              # object.sprite.last_velocity = object.sprite.velocity
  
          # for group in self:
          for controller in self.controllers:
              controller(time_delta, self)