@Override
	public void serviceRemoved(Class<?> interfaceClass, Object service) {
		if (interfaceClass == FieldMouseHandlerService.class && fieldMouseHandlerService != null &&
			fieldMouseHandlerService == service && fieldMouseHandler != null) {
			// Should FieldMouseHandlerService have a removeFieldMouseHandler() method?
			fieldMouseHandlerService = null;
		}
		super.serviceRemoved(interfaceClass, service);
	}
Shows the registers available in a program along with any values that are set.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/register/RegisterPlugin.java