code: public static RxLoaderManager get(FragmentActivity activity) {
          RxLoaderBackendFragmentCompat manager = (RxLoaderBackendFragmentCompat) activity.getSupportFragmentManager().findFragmentByTag(FRAGMENT_TAG);
          if (manager == null) {
              manager = new RxLoaderBackendFragmentCompat();
              activity.getSupportFragmentManager().beginTransaction().add(manager, FRAGMENT_TAG).commit();
          }
          return new RxLoaderManager(manager);
      }
docs: Get an instance of {@code RxLoaderManager} that is tied to the lifecycle of the given {@link
  android.support.v4.app.FragmentActivity}.
  
  @param activity the activity
  @return the {@code RxLoaderManager}