SignatureField gwt.xml problem

Hi all,

I am new to Vaadin and would like to experimentate with the SignatureFild add-on.
after importing the Maven dependency, and compiling the widgetset is see that there is no inherite in the AppWidgetSet.gwt.xml.
If i am importing vaadin charts it does it automatically…

Somebody an idea?

I am using Vaadin8.1.0 with SpringBoot

Thnx