code: public HandlerRegistration setSelectLocationHandler(SelectLocationHandler handler) {
  		if (handlerManager.getHandlerCount(SelectLocationHandler.TYPE) > 0) {
  			SelectLocationHandler previous = handlerManager.getHandler(SelectLocationHandler.TYPE, 0);
  			handlerManager.removeHandler(SelectLocationHandler.TYPE, previous);
  		}
  		return handlerManager.addHandler(SelectLocationHandler.TYPE, handler);
  	}
docs: Set the select location handler.
  <p/>
  There can only be one handler, the default zooms the map widget to the selected location.
  
  @param handler select location handler
  @return handler registration.