code: function(sessionId) {
        if (sessionId) {
          if (sessionId.length < 24) {
            throw new CError('sid length undersized').log();
          }
          if (sessionId.length > 128) {
            throw new CError('sid length exceeded').log();
          }
          this._sid = sessionId;
        }
      }
docs: Set the session identifier
  @param {String} sid The session identifier