code: public BootstrapFeedbackPanel uniqueMessages(){
  		if(filter!=null){
  			setFilter(new AndComposedFeedbackMessageFilter(new UniqueFeedbackMessageFilter(), new ExcludePopoverMessageFilter(), filter));
  		} else {
  			setFilter(new AndComposedFeedbackMessageFilter(new UniqueFeedbackMessageFilter(), new ExcludePopoverMessageFilter()));
  		}
  		return this;
  	}
docs: Enable filter to only display unique feedback messages (enabled by default)
  @return this panel for fluent api