private Path backup() throws IOException {
    Path backup = myTarget.getFileSystem().getPath(myTarget + myBackupExt);
    Files.copy(myTarget, backup, BACKUP_COPY);
    if (SystemInfo.isWindows) {
      DosFileAttributeView dosView = Files.getFileAttributeView(backup, DosFileAttributeView.class);
      if (dosView != null && dosView.readAttributes().isReadOnly()) {
        dosView.setReadOnly(false);
      }
    }
    return backup;
  }
private Path backup()