Changes required in content type
Widget framework 2.x allows filtering of duplicate stories. For that you have to add CssClassAdderDecorator decorator
in the content type for which you want this feature. Say, you want this feature for news
content type.
Then you have to add the following decorator in news content type
<ui:decorator class="com.escenic.framework.decorator.CssClassAdderDecorator"/>
To check details about filtering of duplicate stories please check Widget Framework Developers Guide.