code: def start(self):
      old_current = IOLoop.current(instance=False)
      try:
          self._setup_logging()
          self.make_current()
          self.asyncio_loop.run_forever()
      finally:
          if old_current is None:
              IOLoop.clear_current()
          else:
              old_current.make_current()
  
imports: from __future__ import absolute_import, division, print_function
  import functools
  import tornado.concurrent
  from tornado.gen import convert_yielded
  from tornado.ioloop import IOLoop
  from tornado import stack_context
label_desc: Use image node_id 7 for calling the BaseAsyncIOLoop obj's underlying member method code with example usage: obj.start() without return types