public function delete($id)
    {

        // prepare the pathname to the file containing the session data
        $filename = $this->getSessionSettings()->getSessionFilePrefix() . $id;
        $pathname = $this->getSessionSavePath($filename);

        // remove the session from the file system
        if ($this->removeSessionFile($pathname) === false) {
            throw new SessionCanNotBeDeletedException(
                sprintf('Session with ID %s can not be deleted', $id)
            );
        }
    }