code: def _send_event(self, event_type, **kwargs):
      payload = {"type": event_type}
      payload.update(kwargs)
      for s in self.web_sockets:
          s.send_json(payload)
  
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 12 for calling the FigureManagerWebAgg obj's underlying member method code with example usage: obj._send_event(event_type) without return types