code: private boolean isCurrentBackup(File log)
     {
        for (BackupChain chain : currentBackups)
        {
           if (log.getName().equals(new File(chain.getLogFilePath()).getName()))
           {
              return true;
           }
        }
  
        return false;
     }
docs: isCurrentBackup.
  
  @param log
  File, the log to backup
  @return boolean return the 'true' if this log is current backup.