docs: function Session(connection, id) {
    Session.super_.call(this);
    this._connection = connection;
    this._id = id;
    this._plugins = {};
  
    if (this._connection.getOptions()['keepalive']) {
      this._startKeepAlive();
    }
    var session = this;
    connection.on('close', function() {
      session._destroy();
    });
  }