'Stop an instance in its cell.'

def stop_instance(self, ctxt, instance, do_cast=True, clean_shutdown=True):

    extra_kwargs = dict(clean_shutdown=clean_shutdown)
    if do_cast:
        self._instance_action(ctxt, instance, 'stop_instance', extra_kwargs=extra_kwargs)
    else:
        return self._instance_action(ctxt, instance, 'stop_instance', extra_kwargs=extra_kwargs, need_response=True)
