### Question:
OSGIActivator implements BundleActivator { @Override public void start( BundleContext bundleContext ) throws Exception { this.bundleContext = bundleContext; proxyUnwrapperServiceTracker = new ProxyUnwrapperServiceTracker( bundleContext, osgiPluginTracker ); proxyUnwrapperServiceTracker.open(); osgiPluginTracker.setBundleContext( bundleContext ); osgiPluginTracker.registerPluginClass( BeanFactory.class ); osgiPluginTracker.registerPluginClass( PluginInterface.class ); beanFactoryLookupServiceTracker = new BeanFactoryLookupServiceTracker( bundleContext, osgiPluginTracker ); beanFactoryLookupServiceTracker.open(); pdiPluginSupplementalClassMappingsTrackerForPluginRegistry = new PdiPluginSupplementalClassMappingsTrackerForPluginRegistry( bundleContext ); pdiPluginSupplementalClassMappingsTrackerForPluginRegistry.open(); KarafLifecycleListener.getInstance().setBundleContext( bundleContext ); } OSGIActivator(); BundleContext getBundleContext(); @Override void start( BundleContext bundleContext ); void stop( BundleContext bundleContext );  }### Answer:
@Test public void testStart() throws Exception { osgiActivator.start( bundleContext ); verify( osgiPluginTracker ).setBundleContext( bundleContext ); verify( osgiPluginTracker ).registerPluginClass( BeanFactory.class ); verify( osgiPluginTracker ).registerPluginClass( PluginInterface.class ); }