code: private Destination getOrCreateDestination(final IndividualAddress device,
  		final boolean keepAlive, final boolean verifyByServer)
  	{
  		final Destination d = ((TransportLayerImpl) tl).getDestination(device);
  		return d != null ? d : tl.createDestination(device, true, keepAlive, verifyByServer);
  	}
docs: work around for implementation in TL, which unconditionally throws if dst exists