assertNull(StringUtil.decamelize(null));
        assertEquals("EMP", StringUtil.decamelize("Emp"));
        assertEquals("AAA_BBB", StringUtil.decamelize("aaaBbb"));
        assertEquals("AAA_BBB", StringUtil.decamelize("AaaBbb"));
        assertEquals("AAA_BBB_C", StringUtil.decamelize("aaaBbbC"));
        assertEquals("USER_ID", StringUtil.decamelize("UserId"));
    }

    /**
     * @throws Exception
     */

     * <p>
     * Usage example:
     * </p>
     *
     * <pre>
     * StringUtil.camelize("USER_ID")  = "UserId"
     * </pre>
     *
     * @param s
     *            the text
     * @return the resulting string
     */
    public static String camelize(String s) {
        if (s == null) {
            return null;
        }
        s = s.toLowerCase();

		{"abc", "", "", false},
		{"用戶名", "", "", false},
		{sr("a", nameSize), "", "", false},
		{sr("a", nameSize) + "/", "", "", false},
		{sr("a", nameSize) + "/a", sr("a", nameSize), "a", true},
		{sr("a", prefixSize) + "/", "", "", false},
		{sr("a", prefixSize) + "/a", sr("a", prefixSize), "a", true},
		{sr("a", nameSize+1), "", "", false},
		{sr("/", nameSize+1), sr("/", nameSize-1), "/", true},
		{sr("a", prefixSize) + "/" + sr("b", nameSize),

	// Use long-link files if Name or Linkname exceeds the field size.
	const longName = "././@LongLink"
	if len(hdr.Name) > nameSize {
		data := hdr.Name + "\x00"
		if err := tw.writeRawFile(longName, data, TypeGNULongName, FormatGNU); err != nil {
			return err
		}
	}
	if len(hdr.Linkname) > nameSize {
		data := hdr.Linkname + "\x00"
		if err := tw.writeRawFile(longName, data, TypeGNULongLink, FormatGNU); err != nil {

		formats: FormatUSTAR | FormatPAX | FormatGNU,
	}, {
		header:  &Header{Name: strings.Repeat("a", nameSize)},
		formats: FormatUSTAR | FormatPAX | FormatGNU,
	}, {
		header:  &Header{Name: strings.Repeat("a", nameSize+1)},
		paxHdrs: map[string]string{paxPath: strings.Repeat("a", nameSize+1)},
		formats: FormatPAX | FormatGNU,
	}, {
		header:  &Header{Linkname: "用戶名"},

	magicUSTAR, versionUSTAR = "ustar\x00", "00"
	trailerSTAR              = "tar\x00"
)

// Size constants from various tar specifications.
const (
	blockSize  = 512 // Size of each block in a tar stream
	nameSize   = 100 // Max length of the name field in USTAR format
	prefixSize = 155 // Max length of the prefix field in USTAR format

	// Max length of a special file (PAX header, GNU long name or link).