public function readSession($id = null)
    {
        $id = !isset($id) && isset($this->_sessionId) ? $this->_sessionId : $id;
        if (!isset($id)) {
            return \Reaction\Promise\reject(new Reaction\Exceptions\ErrorException('Param "$id" must be specified in "' . __METHOD__ . '"'));
        }
        return $this->handler->read($id);
    }