A string that uniquely identifies this instance of the class to the server.
The ClientId string is used by the server to uniquely identify each client that is connected to it.
If ClientId is empty when Connect is called, the class's behavior depends on value of CleanSession. If CleanSession is True, the class will automatically generate a unique value for ClientId before connecting. If CleanSession is False, the class fails with an error.
This property is not available at design time.