docs: public static int checkAsyncBackupCount(int currentBackupCount, int newAsyncBackupCount) {
          if (currentBackupCount < 0) {
              throw new IllegalArgumentException("backup-count can't be smaller than 0");
          }
  
          if (newAsyncBackupCount < 0) {
              throw new IllegalArgumentException("async-backup-count can't be smaller than 0");
          }
  
          if (newAsyncBackupCount > MAX_BACKUP_COUNT) {
              throw new IllegalArgumentException("async-backup-count can't be larger than than " + MAX_BACKUP_COUNT);
          }
  
          if (currentBackupCount + newAsyncBackupCount > MAX_BACKUP_COUNT) {
              throw new IllegalArgumentException("the sum of backup-count and async-backup-count can't be larger than than "
                      + MAX_BACKUP_COUNT);
          }
  
          return newAsyncBackupCount;
      }