* StringEscapeUtils.unescapeJava() function in commons-lang that doesn't
     * drop escaped separators (i.e '\,').
     *
     * @param str  the <code>String</code> to unescape, may be null
     * @return the processed string
     * @throws IllegalArgumentException if the Writer is <code>null</code>
     */
    protected static String unescapeJava(String str) {
        if (str == null) {