var errorList []error

	s.preShutdownHookLock.Lock()
	defer s.preShutdownHookLock.Unlock()
	s.preShutdownHooksCalled = true

	for hookName, hookEntry := range s.preShutdownHooks {
		if err := runPreShutdownHook(hookName, hookEntry); err != nil {
			errorList = append(errorList, err)
		}
	}
	return utilerrors.NewAggregate(errorList)
}