Ouzo\Session::startSession PHP Method

    public static function startSession()
    {
        if (version_compare(phpversion(), '5.4.0', '>=') && \PHP_SESSION_ACTIVE === session_status()) {
            throw new RuntimeException('Failed to start the session: already started by PHP.');
        }
        if (version_compare(phpversion(), '5.4.0', '<') && isset($_SESSION) && session_id()) {
            throw new RuntimeException('Failed to start the session: already started by PHP ($_SESSION is set).');
        }
        if (ini_get('session.use_cookies') && headers_sent($file, $line)) {
            throw new RuntimeException(sprintf('Failed to start the session: headers already sent by "%s" at line %d.', $file, $line));
        }
        self::_setSavePath();
        if (!session_start()) {
            throw new RuntimeException('Failed to start the session');
        }
    }