public function setExtension(string $extension): void
    {
        if (!preg_match('/^[a-zA-Z0-9]{2,4}$/', $extension)) {
            throw new InvalidArgumentException(
                'Extension should be only be composed of alphanumeric characters'
                . ' and should be at least 2 but no more than 4 characters'
            );
        }

        $this->extension = $extension;
    }