This annotation can be used to be notified when a component is unregistered from the registry. 
 At this point, the component has been unregistered from the OSGI registry (if it provides some services).
 The method must not take any parameters.
 
 
 
Usage Examples
 
 
 
 @Component
 class X implements Z {     
     @Stop
     void stop(ServiceRegistration sr) {
        // Our service must stop because it is about to be unregistered from the registry.
     }
     
     @Unregistered
     void unregistered() {
        // At this point, our service has been unregistered from the OSGi registry
     }
 }