    private static function validateCustomError(array &$filters, string $field)
    {
        $customError = null;
        if (array_key_exists('error', $filters)) {
            $customError = $filters['error'];
            if (!is_string($customError) || trim($customError) === '') {
                throw new InvalidArgumentException("error for field '{$field}' was not a non-empty string");
            }

            unset($filters['error']);//unset so its not used as a filter
        }

        return $customError;
    }