Asterisk Java :Error on using getConnectedlinenum()


I just started developing with the asterisk java framework.
I want to use the Class ManagerEvent and its subclass DialEvent for
logging who dialed who for example. I can return the number of the Caller, with getCallerIdnum(),
but for getConnectedlinenum() I get a “not defind for this method”- error, although its written in the API.
So this works:

if(event instanceof DialEvent){

		  System.out.println("Caller ID: " +  ((DialEvent) event).getCallerIdNum());


but this not:

if(event instanceof DialEvent){
System.out.println("Angerufener: " + ((DialEvent) event).getConnectedlinename());


Thank you very much for reading, i hope you can help me.

best wishes

may be I just have to accept, that the asterisk java API docs are not the best documented?! :frowning: