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------"));

          <description>
            The permissions for files when they are created.
          </description>
          <type>String</type>
        </field>
        <field>
          <name>directoryPermissions</name>
          <version>1.0.0+</version>
          <description>
            The permissions for directories when they are created.
          </description>
          <type>String</type>
        </field>