Google Sign in component: Vaadin 10 Java integration of Google Sign in -webcomponent
To use this, you need Google Client Id, for instructions see:
(In short, you need to create an app in https://console.developers.google.com and get id from there, also if you want to use this in a real server, you need allow domain and prove that you own the domain, but in development at localhost, only the client id is enough)