@SuppressWarnings("unchecked")
    @CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    public final <R> Maybe<R> compose(MaybeTransformer<? super T, ? extends R> transformer) {
        return wrap(((MaybeTransformer<T, R>) ObjectHelper.requireNonNull(transformer, "transformer is null")).apply(this));
    }