@SuppressWarnings("rawtypes")
    public static void setOnMaybeSubscribe(@Nullable BiFunction<? super Maybe, MaybeObserver, ? extends MaybeObserver> onMaybeSubscribe) {
        if (lockdown) {
            throw new IllegalStateException("Plugins can't be changed anymore");
        }
        RxJavaPlugins.onMaybeSubscribe = onMaybeSubscribe;
    }