for (byte b : bytes) {
      sb.append(hexDigits[(b >> 4) & 0xf]).append(hexDigits[b & 0xf]);
    }
    return sb.toString();
  }

  private static final char[] hexDigits = "0123456789abcdef".toCharArray();

func isHexes(s string) bool {
	if s == "" {
		return false
	}
	if s == "empty" {
		return true
	}
	for _, f := range strings.Split(s, " or ") {
		if f == "" || len(f)%2 != 0 || strings.TrimLeft(f, "0123456789abcdef") != "" {
			return false
		}
	}
	return true
}

// It would be nice if the error messages always began with
// the standard file:line: prefix,
// but that's not where we are today.

        assertEquals("XXFFXXXXXX", new String(dst3));

        // Test long conversion
        char[] dst4 = new char[16];
        Hexdump.toHexChars(0x123456789ABCDEF0L, dst4, 0, 16);
        assertEquals("123456789ABCDEF0", new String(dst4));
    }

    @Test
    @DisplayName("Should verify HEX_DIGITS constant")
    void testHexDigitsConstant() {
        // Verify the HEX_DIGITS array contains correct values

	if err != nil {
		t.Fatalf("%s: <ERROR> %s", instanceType, err)
	}
	uploadID := res.UploadID

	// Create a byte array of 5MiB.
	data := bytes.Repeat([]byte("0123456789abcdef"), 5*humanize.MiByte/16)
	completedParts := CompleteMultipartUpload{}
	for i := 1; i <= 10; i++ {
		expectedETaghex := getMD5Hash(data)

		var calcPartInfo PartInfo

	response, err := s.client.Do(request)
	c.Assert(err, nil)
	c.Assert(response.StatusCode, 200)

	// Create a byte array of 5MB.
	// content for the object to be uploaded.
	data := bytes.Repeat([]byte("0123456789abcdef"), 5*humanize.MiByte/16)
	// calculate etag of the data.
	etagBase64 := getMD5HashBase64(data)

	buffer1 := bytes.NewReader(data)
	objectName := "test-1-object"

   * "12AB" is the four hexadecimal digits representing the 16-bit code unit.
   */
  private static String showCharacter(char c) {
    String hex = "0123456789ABCDEF";
    char[] tmp = {'\\', 'u', '\0', '\0', '\0', '\0'};
    for (int i = 0; i < 4; i++) {
      tmp[5 - i] = hex.charAt(c & 0xF);
      c = (char) (c >> 4);
    }
    return String.copyValueOf(tmp);
  }

				for i := 0; i < b.N; i++ {
					LastIndexAny(x[:k], cs[:j])
				}
			})
		}
	}
}

func BenchmarkTrimASCII(b *testing.B) {
	cs := "0123456789abcdef"
	for k := 1; k <= 4096; k <<= 4 {
		for j := 1; j <= 16; j <<= 1 {
			b.Run(fmt.Sprintf("%d:%d", k, j), func(b *testing.B) {
				x := Repeat([]byte(cs[:j]), k) // Always matches set