public static function checkFactUnique(array $uniquefacts, Collection $recfacts): array
    {
        foreach ($recfacts as $factarray) {
            $fact = $factarray->getTag();

            $key = array_search($fact, $uniquefacts, true);
            if ($key !== false) {
                unset($uniquefacts[$key]);
            }
        }

        return $uniquefacts;
    }