private boolean checkBackupDelay(long backupDelay){
  long ago=System.currentTimeMillis() - lastBackup;
  return ago > backupDelay;
}

private boolean checkBackupDelay ( long backupDelay ) { long ago = System . currentTimeMillis ( ) - lastBackup ; return ago > backupDelay ; }
checks if the given delay has passed since the last backup . should be checked only after loading the metadata .
