sprockets/src/main/java/net/sf/sprockets/app/Fragments.java
@Nullable
    public static <T extends Fragment> T findById(Activity a, @IdRes int id) {
        return findById(a.getFragmentManager(), id);
    }
@Nullable
    public static <T extends Fragment> T findById(Activity a, @IdRes int id) {
        return findById(a.getFragmentManager(), id);
    }
Get the Fragment with the ID.

@return null if the Fragment isn't found
@since 4.0.0