/**
     * The default charset.
     */
    public static final Charset DEFAULT_CHARSET;

    /**
     * The ISO date-time format.
     */
    public static final String ISO_DATETIME_FORMAT = "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'";

    /**
     * The feature for secure processing in XML.
     */
    public static final String FEATURE_SECURE_PROCESSING = "http://javax.xml.XMLConstants/feature/secure-processing";

     */
    private String loc;

    /**
     * The date of last modification of the file. This date should be in W3C
     * Datetime format. This format allows you to omit the time portion, if
     * desired, and use YYYY-MM-DD.
     *
     * Note that this tag is separate from the If-Modified-Since (304) header
     * the server can return, and search engines may use the information from
     * both sources differently.
     */