enc = "S-JIS";
        assertEquals("S-JIS", encodingHelper.normalize(enc));
    }

    public void test_normalize_map() {
        String enc;

        encodingHelper.addEncodingMapping("S-JIS", "Shift_JIS");

        enc = "UTF-8";
        assertEquals("UTF-8", encodingHelper.normalize(enc));

        enc = "Shift_JIS";
        assertEquals("Shift_JIS", encodingHelper.normalize(enc));

     *
     * @param source the source encoding name
     * @param target the target encoding name
     * @throws IllegalArgumentException if source or target is blank
     */
    public void addEncodingMapping(final String source, final String target) {
        if (StringUtil.isBlank(source) || StringUtil.isBlank(target)) {
            throw new IllegalArgumentException("Source and target encodings must not be blank.");
        }