private static final PermissionSupplier directoryPermissions;

    static {
      Set<String> views = FileSystems.getDefault().supportedFileAttributeViews();
      if (views.contains("posix")) {
        filePermissions = () -> asFileAttribute(PosixFilePermissions.fromString("rw-------"));
        directoryPermissions = () -> asFileAttribute(PosixFilePermissions.fromString("rwx------"));