code: def _inner_close(self):
      if self.client is not None:
          self.client.close()
          self.client = None
          if self._event_loop.is_running():
              self._event_loop.stop()
          self._event_loop = None
  
file_path: nni/nni/tools/trial_tool/web_channel.py
imports: import asyncio
  import os
  import websockets
  from .base_channel import BaseChannel
  from .log_utils import LogType, nni_log
label_desc: Use image node_id 3 for calling the WebChannel obj's underlying member method code with example usage: obj._inner_close() without return types