class_docstr: EGL backend for Canvas abstract class.
code: def _on_draw(self, _id=None):
      # This is called by the processing app
      if self._vispy_canvas is None or self._surface is None:
          return
      self._vispy_canvas.set_current()
      self._vispy_canvas.events.draw(region=None)
  
imports: from __future__ import division
  import atexit
  from time import sleep
  from ..base import BaseApplicationBackend, BaseCanvasBackend, BaseTimerBackend
  from ...util.ptime import time
  from ...None import config
label_desc: Use image node_id 14 for calling the CanvasBackend obj's underlying member method code with example usage: obj._on_draw(_id) without return types