code: def stop(self):
          
  
          yield from self._stop_ubridge()
          with (yield from self._execute_lock):
              # stop the QEMU process
              self._hw_virtualization = False
              if self.is_running():
                  log.info('Stopping QEMU VM "{}" PID={}'.format(self._name, self._process.pid))
                  try:
                      if self.acpi_shutdown:
                          yield from self._control_vm("system_powerdown")
                          yield from gns3server.utils.asyncio.wait_for_process_termination(self._process, timeout=30)
                      else:
                          self._process.terminate()
                          yield from gns3server.utils.asyncio.wait_for_process_termination(self._process, timeout=3)
                  except ProcessLookupError:
                      pass
                  except asyncio.TimeoutError:
                      if self._process:
                          try:
                              self._process.kill()
                          except ProcessLookupError:
                              pass
                          if self._process.returncode is None:
                              log.warn('QEMU VM "{}" PID={} is still running'.format(self._name, self._process.pid))
              self._process = None
              self._stop_cpulimit()
              yield from super().stop()
docs: Stops this QEMU VM.