HashSet<String> () { HashSet<String> ids = knownInspectionIds; if (ids != null) { return ids; } // slow path if (!listenerSetUp) { synchronized (InspectionToolValidator.class) { if (!listenerSetUp) { ApplicationManager.getApplication().getMessageBus().connect().subscribe(DynamicPluginListener.TOPIC, new InspectionIdsPluginListener()); listenerSetUp = true; } } } HashSet<String> computed = collectKnownInspectionIds(); knownInspectionIds = computed; return computed; }