code: @TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1)
      public static RxLoaderManager get(Fragment fragment) {
          if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR1) {
              throw new UnsupportedOperationException("Method only valid in api 17 and above, use RxLoaderManagerCompat to support older versions (requires support library)");
          }
  
          RxLoaderBackendNestedFragment manager = (RxLoaderBackendNestedFragment) fragment.getChildFragmentManager().findFragmentByTag(FRAGMENT_TAG);
  
          if (manager == null) {
              manager = new RxLoaderBackendNestedFragment();
              fragment.getChildFragmentManager().beginTransaction().add(manager, FRAGMENT_TAG).commit();
          }
          return new RxLoaderManager(manager);
      }
docs: Get an instance of the {@code RxLoaderManager} that is tied to the lifecycle of the given
  {@link android.app.Fragment}. If you are using the support library, then you should use
  {@link me.tatarka.rxloader.RxLoaderManagerCompat#get(android.support.v4.app.Fragment)}}
  instead.
  
  @param fragment the fragment
  @return the {@code RxLoaderManager}