code: public static Message buildSnapshotDone(String filePath) {
      ZabMessage.SnapshotDone done =
        ZabMessage.SnapshotDone.newBuilder().setFilePath(filePath).build();
      return Message.newBuilder().setType(MessageType.SNAPSHOT_DONE)
                                 .setSnapshotDone(done).build();
    }
docs: Creates the SNAPSHOT_DONE message.
  
  @param filePath the file path for the snapshot.
  @return a protobuf message.