https://cdn.vaadin.com/vaadin-lumo-styles/1.0.0/demo/badges.html
sayHello = new Button("Say hello");
sayHello.addThemeVariants(ButtonVariant.LUMO_PRIMARY,ButtonVariant.LUMO_SUCCESS);

IBM Integration Bus Development, Training and Support
https://cdn.vaadin.com/vaadin-lumo-styles/1.0.0/demo/badges.html
sayHello = new Button("Say hello");
sayHello.addThemeVariants(ButtonVariant.LUMO_PRIMARY,ButtonVariant.LUMO_SUCCESS);