Accessing elements based on a mix of Vaadin 7 and 8 with TestBench?

Hello,

The application our team develops started with Vaadin 7 and later on introduced Vaadin 8. However there are still components being used which are based on Vaadin 7.

When evaulating the Vaadin Testbench (5.1.2) I discovered that I could not access elements based on Vaadin 7 with $(TextFieldElement.class).first(). So I switched to Testbench 4.2.1 and could access the Vaadin 7 components.

But is Testbench 4.x capable of accessing Vaadin 8 components? If not, what would I need to do to access both components, Vaadin 7 and 8?