Validating fields using Regular Expressions in Vaadin 8

How do you validate user input from a fiel using regular expressions in Vaadin 8?
The previous addValidator() method has been removed in Vaadin 8
Any assistance provided would be highly appreciated

Check the new Binder and its API (it uses fluent syntax), e.g. withValidator()

https://vaadin.com/api/8.0.1/com/vaadin/data/Binder.html