public static void runExample(
DfpServices dfpServices, DfpSession session, long creativeSetId, long companionCreativeId)
throws Exception {
// Get the CreativeSetService.
CreativeSetServiceInterface creativeSetService =
dfpServices.get(session, CreativeSetServiceInterface.class);
// Get the creative set.
CreativeSet creativeSet = creativeSetService.getCreativeSet(creativeSetId);
// Add the companion creative to the creative set.
creativeSet.setCompanionCreativeIds(
Longs.concat(creativeSet.getCompanionCreativeIds(), new long[] {companionCreativeId}));
// Update the creative set on the server.
CreativeSet updatedCreativeSet = creativeSetService.updateCreativeSet(creativeSet);
System.out.printf("A creative set with ID \"%d\", master creative ID \"%d\", "
+ "and companion creative IDs [%s] was updated.", updatedCreativeSet.getId(),
updatedCreativeSet.getMasterCreativeId(),
Longs.join(",", updatedCreativeSet.getCompanionCreativeIds()));