import org.bukkit.event.server.ServiceUnregisterEvent; //导入依赖的package包/类
private ServiceCallback(Class<T> serviceClass) {
    this.serviceClass = serviceClass;
    refresh();

    // listen for service updates
    this.listener = Events.merge(ServiceEvent.class, ServiceRegisterEvent.class, ServiceUnregisterEvent.class)
            .filter(e -> e.getProvider() != null && e.getProvider().getService().equals(serviceClass))
            .handler(e -> refresh());
}
 

import org.bukkit.event.server.ServiceUnregisterEvent; //导入依赖的package包/类
@EventHandler
public void onServiceChange(ServiceUnregisterEvent e) {
    if (e.getProvider().getService() == Chat.class) {
        refreshVault();
    }
}