/**
         * This method check for user authorization to an app
         *
         * @param AccessCheck $accessCheck - The app and user credentials
         *
         * @return array user authorization
         */
        public function CheckAccess(AccessCheck $accessCheck) {
            $sql = "SELECT grade, department FROM acl WHERE app=:app";
            $stmt = $this->connection->prepare($sql);
            $stmt->execute(['app' => $accessCheck->app]);
            $access = $stmt->fetch();
            var_dump($access);
            var_dump($access['grade']);
            var_dump((int) $accessCheck->grade - 1);
            var_dump(substr($access['grade'], (int) $accessCheck->grade - 1,1));
            var_dump(substr($access['department'], (int) $accessCheck->department - 1,1));
            if((substr($access['grade'],(int) $accessCheck->grade - 1, 1) === "1") ||
              ((substr($access['grade'], (int) $accessCheck->grade - 1, 1) === "1") &&
               (substr($access['department'], (int) $accessCheck->department - 1, 1) === "1"))) {
                return "Granted";
            } else {
                return "Denied";
            }
        }