code: function(callback) {
        var t = this;
        callback = callback || function(){};
        var onPong = function() {
          t.off('pong', onPong);
          callback();
        };
        t.on('pong', onPong);
        t.emit('connection:ping');
      }
docs: Ping a remote connection
  
  @method ping
  @param callback {Function(error)} Callback when response is returned