docs: private byte[] encode(Message msg, String apiVersion, String kind) {
      // It is unfortunate that we have to include apiVersion and kind,
      // since we should be able to extract it from the Message, but
      // for now at least, those fields are missing from the proto-buffer.
      Unknown u =
          Unknown.newBuilder()
              .setTypeMeta(TypeMeta.newBuilder().setApiVersion(apiVersion).setKind(kind))
              .setRaw(msg.toByteString())
              .build();
      return Bytes.concat(MAGIC, u.toByteArray());
    }