migration 6.8.3 to 7.2.2

I’m migration a Liferay Vaadin project form 6.8.3 to 7.2.2. I’m encountering an issue with the class AbstractApplicationPortlet, i don’t really know to replace it with the new version.
Can someone give me a hand here ?

Thank you.

I think that AbstractApplicationPortlet is replaced with the VaadinPortlet in Vaadin 7… Could you elaborate your issue little bit more?