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------"));

       * to test it.
       */
      return;
    }

    /*
     * Only under Windows (or hypothetically when running with some other non-POSIX, ACL-based
     * filesystem) does our prod code look up the username. Thus, this test doesn't necessarily test
     * anything interesting under most environments. Still, we can run it (except for Android, at

       * to test it.
       */
      return;
    }

    /*
     * Only under Windows (or hypothetically when running with some other non-POSIX, ACL-based
     * filesystem) does our prod code look up the username. Thus, this test doesn't necessarily test
     * anything interesting under most environments. Still, we can run it (except for Android, at