private function activeDeclaration(int $tokenID): string
    {
        foreach ($this->declarations as $declarations) {
            foreach ($declarations as $name => $position) {
                if ($tokenID >= $position[self::O_TOKEN] && $tokenID <= $position[self::C_TOKEN]) {
                    return $name;
                }
            }
        }

        //Can not be detected
        return '';
    }