Class UniversalActionResponse

// A universal action that opens a link.
const openLinkUniversalAction =
    AddOnsResponseService.newUniversalActionResponseBuilder()
        .setOpenLink(AddOnsResponseService.newOpenLink().setUrl('https://www.google.com'))
        .build();

const cardBuilder1 = CardService.newCardBuilder();
const cardBuilder2 = CardService.newCardBuilder();
// Finish building the cards ...

// A universal action that shows two static cards.
const cardsUniversalAction =
    AddOnsResponseService.newUniversalActionResponseBuilder()
        .displayAddOnCards([cardBuilder1.build(), cardBuilder2.build()])
        .build();