The following snippet of code shows a typical way of extending VerticalLayout to implement a UI component, in this case, the login form:

public class LoginFormLayout extends VerticalLayout {

    private TextField username = new PasswordField();
    private PasswordField password = new PasswordField();
    private Button logIn = new Button();
    private CheckBox rememberMe = new CheckBox();
 
    public LoginFormLayout() {
        ...
        addComponents(username, password, logIn, rememberMe);
    }
    ...
}

The logic to handle events and additional UI configuration that might be required is omitted in the previous example.