defer s.preShutdownHookLock.Unlock()

	if s.preShutdownHooksCalled {
		return fmt.Errorf("unable to add %q because PreShutdownHooks have already been called", name)
	}
	if _, exists := s.preShutdownHooks[name]; exists {
		return fmt.Errorf("unable to add %q because it is already registered", name)
	}

	s.preShutdownHooks[name] = preShutdownHookEntry{hook: hook}

	return nil
}

	UnprotectedHandler() http.Handler

	// PostStartHooks returns the post-start hooks that need to be combined
	PostStartHooks() map[string]postStartHookEntry

	// PreShutdownHooks returns the pre-stop hooks that need to be combined
	PreShutdownHooks() map[string]preShutdownHookEntry

	// HealthzChecks returns the healthz checks that need to be combined
	HealthzChecks() []healthz.HealthChecker

		}
	}

	// first add poststarthooks from delegated targets
	for k, v := range delegationTarget.PostStartHooks() {
		s.postStartHooks[k] = v
	}

	for k, v := range delegationTarget.PreShutdownHooks() {
		s.preShutdownHooks[k] = v
	}

	// add poststarthooks that were preconfigured.  Using the add method will give us an error if the same name has already been registered.

//	                                 stopCh
//	                                   |
//	             |--------------------------------------------|
//	             |                                            |
//		    call PreShutdownHooks                        (ShutdownInitiated)
//	             |                                            |
//	  (PreShutdownHooksStopped)                   Sleep(ShutdownDelayDuration)