code: public void notifyPackageAdded(String packageName) {
      for (Pair<LauncherApps.Callback, Handler> callbackPair : callbacks) {
        callbackPair.second.post(
            () -> callbackPair.first.onPackageAdded(packageName, Process.myUserHandle()));
      }
    }
docs: Fires {@link LauncherApps.Callback#onPackageAdded(String, UserHandle)} on all of the registered
  callbacks, with the provided packageName.
  
  @param packageName the package the was added.