code: def _timer_stop(self):
      if self._timer is None:
          return
      elif self._single:
          ioloop = tornado.ioloop.IOLoop.instance()
          ioloop.remove_timeout(self._timer)
      else:
          self._timer.stop()
  
      self._timer = None
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import six
  import datetime
  import io
  import json
  import os
  import warnings
  import numpy
  import tornado
  from matplotlib.backends import backend_agg
  from matplotlib.backend_bases import _Backend
  from matplotlib import backend_bases
  from matplotlib import _png
label_desc: Use image node_id 2 for calling the TimerTornado obj's underlying member method code with example usage: obj._timer_stop() without return types