code: public HandlerRegistration setSelectAlternativeHandler(SelectAlternativeHandler handler) {
  		if (handlerManager.getHandlerCount(SelectAlternativeHandler.TYPE) > 0) {
  			SelectAlternativeHandler previous = handlerManager.getHandler(SelectAlternativeHandler.TYPE, 0);
  			handlerManager.removeHandler(SelectAlternativeHandler.TYPE, previous);
  		}
  		return handlerManager.addHandler(SelectAlternativeHandler.TYPE, handler);
  	}
docs: Set the select alternative handler.
  <p/>
  There can only be one handler, the default displays the alternatives in a window on the map widget.
  
  @param handler select alternative handler
  @return handler registration.