vaadin-framework/client/src/com/vaadin/DefaultWidgetSet.gwt.xml

<module>
    <!-- This GWT module defines the Vaadin DefaultWidgetSet. This is the 
        module you want to extend when creating an extended widget set, or when creating 
        a specialized widget set with a subset of the components. -->

    <!-- Hint for WidgetSetBuilder not to automatically update the file -->
    <!-- WS Compiler: manually edited -->

    <inherits name="com.vaadin.Vaadin" />

    <entry-point class="com.vaadin.client.ApplicationConfiguration" />

</module>