code: function(hostName, appName, appInstance) {
        var t = this, thisInstance = 0;
        return t.connections.find(function(conn) {
  
          // Host or app matches if not specified or if specified and equal
          var matchesHost = !hostName || conn.isThisHost(hostName);
          var matchesApp = !appName || appName === conn.get('remoteAppName');
          var matchesInstance = !appInstance || appInstance === conn.get('remoteAppInstance');
          var remoteFirewall = conn.get('remoteFirewall');
  
          // This is a match if host + app + instance matches, and it's not firewalled
          return (!remoteFirewall && matchesHost && matchesApp && matchesInstance);
        });
      }
docs: Find an existing connection to use
  
  This method looks into the existing known connections to find one
  that matches the specified parameters.
  
  Firewalled connections are not returned.
  
  @method findConnection
  @protected
  @param hostName {String} - Host name to find a connection for (null = any host)
  @param appName {String} - App name to find a connection with (null = any app)
  @param appInstance {Any} - Application instance running on this host (null = any instance)
  @return connection {Connection} - A Connection object if found, otherwise null