static final long EXPONENT_MASK = 0x7ff0000000000000L;

  // The mask for the sign, according to the {@link
  // Double#doubleToRawLongBits(double)} spec.
  static final long SIGN_MASK = 0x8000000000000000L;

  static final int SIGNIFICAND_BITS = 52;

  static final int EXPONENT_BIAS = 1023;

  /** The implicit 1 bit that is omitted in significands of normal doubles. */

  static final long EXPONENT_MASK = 0x7ff0000000000000L;

  // The mask for the sign, according to the {@link
  // Double#doubleToRawLongBits(double)} spec.
  static final long SIGN_MASK = 0x8000000000000000L;

  static final int SIGNIFICAND_BITS = 52;

  static final int EXPONENT_BIAS = 1023;

  /** The implicit 1 bit that is omitted in significands of normal doubles. */

    }

    @Test
    @DisplayName("Should convert long to hex string with padding")
    void testLongToHexString() {
        // Test various long values
        assertEquals("0000000000000000", Hexdump.toHexString(0L, 16));
        assertEquals("00000000000000FF", Hexdump.toHexString(255L, 16));
        assertEquals("FFFFFFFFFFFFFFFF", Hexdump.toHexString(-1L, 16));

        // Test different sizes

     *
     */
    private static final String HMAC_KEY = "HMAC";
    private static final byte[] MD5_CONSTANT = "signaturekey\0".getBytes(StandardCharsets.US_ASCII);
    private static final byte[] ZERO_IV = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

    /**
     * Calculates a MAC using the ARCFOUR-HMAC-MD5 algorithm.
     * This method implements the Microsoft variant of the Kerberos ARCFOUR-HMAC-MD5 checksum.
     *