@CheckReturnValue
    @NonNull
    @SchedulerSupport(SchedulerSupport.NONE)
    public static <T> Maybe<T> unsafeCreate(MaybeSource<T> onSubscribe) {
        if (onSubscribe instanceof Maybe) {
            throw new IllegalArgumentException("unsafeCreate(Maybe) should be upgraded");
        }
        ObjectHelper.requireNonNull(onSubscribe, "onSubscribe is null");
        return RxJavaPlugins.onAssembly(new MaybeUnsafeCreate<T>(onSubscribe));
    }