### Question:
OSGIServiceTracker extends ServiceTracker { @Override public void modifiedService( ServiceReference reference, Object service ) { tracker.serviceChanged( clazzToTrack, LifecycleEvent.MODIFY, reference ); super.modifiedService( reference, service ); } OSGIServiceTracker( OSGIPluginTracker tracker, Class clazzToTrack );  OSGIServiceTracker( OSGIPluginTracker osgiPluginTracker, Class clazzToTrack, boolean asPluginInterface ); @Override Object addingService( ServiceReference
                                 reference ); @Override void removedService( ServiceReference
                                reference, Object service ); @Override void modifiedService( ServiceReference
                                 reference, Object service );  }### Answer:
@Test public void testModifiedService() { ServiceReference serviceReference = mock( ServiceReference.class ); Object service = mock( Object.class ); new OSGIServiceTracker( pluginTracker, Object.class ).modifiedService( serviceReference, service ); verify( pluginTracker ).serviceChanged( Object.class, MODIFY, serviceReference ); }