String input = "Test\u0001\u0002\u0008Valid\u000B\u000C\u000EText";
        String result = XmlUtil.stripInvalidXMLCharacters(input);
        assertEquals("TestValidText", result);
    }

    public void test_stripInvalidXMLCharacters_validRanges() {
        // Test valid character ranges
        String input = "Test" + String.valueOf((char) 0x0020) // space