Can't find .setClearButtonVisible() method

I can’t seem to find the .setClearButtonVisible() method for both DatePicker and ComboBox components. I can see the method in the API pages but when i try to use it in my code it’s not showed in the method list.
I’m using Vaadin 8 with SpringBoot and IntelliJ

Sounds like you’re mixing up Vaadin 14 and Vaadin 8. Vaadin 8 doesn’t have a component called DatePicker and ComboBox doesn’t have a clear button in Vaadin 8.

But then why all the components and the methods are working fine except for this one method? I’m using the DatePicker just fine except for .setClearButton() method?

That screenshot is not from a Vaadin 8 app, I can tell from the theme; it’s Lumo theme which was introduced in Vaadin 10.