serialdispatcher.go
func NewSerialDispatcher(handlers []Handler) Dispatcher {
	return &SerialDispatcher{
		handlers: handlers,
		mutex:    sync.RWMutex{},
	}
}
func NewSerialDispatcher(handlers []Handler) Dispatcher {
	return &SerialDispatcher{
		handlers: handlers,
		mutex:    sync.RWMutex{},
	}
}
// NewSerialDispatcher creates a new PrallelDispatcher with the given handlers