docs: function(config) {
        config = config || {};
        this._reply = config.reply || false;
        this.setMode(config.mode || 'auth');
        this.setSid(config.sid);
        this.setDate(config.date || new Date());
        this.keychain = new Crypter({
          key : config.key,
          cert: config.cert
        });
        this.encoder = new Crypter({
          cert: config.encoderCert
        });
      }