if the code is right, the code is not removed

[FantasyLeo]

in "captcha/src/Captcha.php"

    public function check($value)
    {
        if ( ! $this->session->has('captcha'))
        {
            return false;
        }
        $key = $this->session->get('captcha.key');
        if ( ! $this->session->get('captcha.sensitive'))
        {
            $value = $this->str->lower($value);
        }
        $this->session->remove('captcha');
        return $this->hasher->check($value, $key);
    }

$this->session->remove('captcha'); // doesn't work