static <DocApiT extends Routable, ProtoT extends AbstractMessage> ProtobufCodecBuilder<DocApiT, ProtoT>
        of(Class<DocApiT> apiClass, Class<ProtoT> protoClass) {
            return new ProtobufCodecBuilder<>(apiClass, protoClass);
        }
Implementation of MessageBus message request/response serialization built around Protocol Buffers.
documentapi/src/main/java/com/yahoo/documentapi/messagebus/protocol/RoutableFactories80.java