tracker.getData().add(new Object());
tracker.getData().add(new Object());
assertFalse(tracker.getData().isEmpty());
TrackingPlugin rc = new TrackingPlugin();
rc.start(plugin.getBundle().getBundleContext());
Field field = TrackingPlugin.class.getDeclaredField("trackers");
field.setAccessible(true);
field.set(rc, ImmutableSet.<ITracker<?>> of(tracker));