Your example would look like this in SDK3:
MutateInResult result = collection.mutateIn(campaignEntity.getId(), Arrays.asList(
MutateInSpec.upsert("a", entity.getA),
MutateInSpec.upsert("b", entity.getB)));
Your example would look like this in SDK3:
MutateInResult result = collection.mutateIn(campaignEntity.getId(), Arrays.asList(
MutateInSpec.upsert("a", entity.getA),
MutateInSpec.upsert("b", entity.getB)));