code: def draw(self):
      renderer = self.get_renderer(cleared=True)
  
      self._png_is_old = True
  
      backend_agg.RendererAgg.lock.acquire()
      try:
          self.figure.draw(renderer)
      finally:
          backend_agg.RendererAgg.lock.release()
          # Swap the frames
          self.manager.refresh_all()
  
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 3 for calling the FigureCanvasWebAggCore obj's underlying member method code with example usage: obj.draw() without return types