/** * Utility method throwing an exception if the stack is not properly initialized. * * @throws java.lang.IllegalStateException if the underlying stack is not registered and * initialized. */ private void assertConnected() throws IllegalStateException { if (opSetPersPresence == null) { throw new IllegalStateException( "The provider must be signed on the service before" + " being able to communicate."); } else opSetPersPresence.assertConnected(); }