code: def move_state(self, direction, activate):
          
          if direction == RIGHT:
              self._xdir = POSITIVE if activate else STILL
          elif direction == LEFT:
              self._xdir = NEGATIVE if activate else STILL
          elif direction == FORWARD:
              self._zdir = NEGATIVE if activate else STILL
          elif direction == BACKWARD:
              self._zdir = POSITIVE if activate else STILL
          elif direction == UP:
              self._ydir = POSITIVE if activate else STILL
          elif direction == DOWN:
              self._ydir = NEGATIVE if activate else STILL
docs: Set the camera position move state
  
          :param direction: What direction to update
          :param activate: Start or stop moving in the direction