code: public static RxLoaderManager get(Fragment fragment) {
          RxLoaderBackendNestedFragmentCompat manager = (RxLoaderBackendNestedFragmentCompat) fragment.getChildFragmentManager().findFragmentByTag(FRAGMENT_TAG);
          if (manager == null) {
              manager = new RxLoaderBackendNestedFragmentCompat();
              fragment.getChildFragmentManager().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.Fragment}.
  
  @param fragment the fragment
  @return the {@code RxLoaderManager}