code: def handle_send_image_mode(self, event):
      # The client requests notification of what the current image mode is.
      self.send_event("image_mode", mode=self._current_image_mode)
  
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 17 for calling the FigureCanvasWebAggCore obj's underlying member method code with example usage: obj.handle_send_image_mode(event) without return types