gwt-connectors: How to find out which widgets a connector is conntected?

[Janine Joachim]

I have a panel where i can add widgets and connectors. How can I programmatically find out which widgets are connected to other widgets? I have tried the following:

Connector con = new Connector(x, y, 500, y, null, new SectionDecoration(DecorationType.ARROW_SOLID));
con.style = ConnectorStyle.SOLID;
con.showOnDiagram(diagram);  
.....
//some Shaped Widgets
....
if(con.startEndPoint.isGluedToConnectionPoint())
                    {
                       //add Label to PopUp-Panel
                        pop.addChild(label); 
                    }
.....

the if-condition is not working, but i don't know whats wrong. Can anybody help me? Thanks