code: def stop(self, timeout=1.0):
          
          if timeout:
              self._running.wait(timeout)
          return self._ioloop_manager.stop(callback=self._uninstall)
docs: Stop a running server (from another thread).
  
          Parameters
          ----------
          timeout : float or None, optional
              Seconds to wait for server to have *started*.
  
          Returns
          -------
          stopped : thread-safe Future
              Resolves when the server is stopped