private function filterFieldsByWhiteList(\ArrayIterator $allowedFields, array $listToClean)
    {
        $allowedFieldsLowerCase = array_map('strtolower', (array)$allowedFields);
        $cleanedList = array_filter($listToClean, function ($field) use ($allowedFieldsLowerCase) {
            return in_array(strtolower($field), $allowedFieldsLowerCase);
        }, ARRAY_FILTER_USE_KEY);

        return $cleanedList;
    }