code: public int updateProgress() throws CommandExecutionException {
          int resp = sendToArray("miIO.get_ota_progress").optInt(0, -1);
          if ((resp < 0) || (resp > 100)) throw new CommandExecutionException(CommandExecutionException.Error.INVALID_RESPONSE);
          return resp;
      }
docs: Request the update progress as a percentage value from 0 to 100
  @return The current progress.
  @throws CommandExecutionException When there has been a error during the communication or the response was invalid.