docs: def call_nowait(self, cb_name):
          """ pick a callback command and call it without waiting for it to finish """
          if self.bootstrapping:
              return
          if cb_name in (ACTION_ON_START, ACTION_ON_STOP, ACTION_ON_RESTART, ACTION_ON_ROLE_CHANGE):
              self.__cb_called = True
  
          if self.callback and cb_name in self.callback:
              cmd = self.callback[cb_name]
              try:
                  cmd = shlex.split(self.callback[cb_name]) + [cb_name, self.role, self.scope]
                  self._callback_executor.call(cmd)
              except Exception:
                  logger.exception('callback %s %s %s %s failed', cmd, cb_name, self.role, self.scope)