code: def _vispy_stop(self):
      pyglet.clock.unschedule(self._vispy_timer._timeout)
  
imports: from __future__ import division
  from packaging.version import Version
  from time import sleep
  from ..base import BaseApplicationBackend, BaseCanvasBackend, BaseTimerBackend
  from ...util import keys
  from ...util.ptime import time
  from ...None import config
label_desc: Use image node_id 2 for calling the TimerBackend obj's underlying member method code with example usage: obj._vispy_stop() without return types