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. */

    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 = new byte[] {
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
    };


    public static byte[] calculateMacArcfourHMACMD5 ( int keyusage, Key key, byte[] data ) throws GeneralSecurityException {
        int ms_usage = mapArcfourMD5KeyUsage(keyusage);

		{"0000000000000000", 0, ""},
		{"0000000000000001", 1, ""},
		{"ffffffffffffffff", 1<<64 - 1, ""},
		{"FFFFFFFFFFFFFFFF", 1<<64 - 1, ""},
		{"000000000000bogus", 0, "invalid byte in chunk length"},
		{"00000000000000000", 0, "http chunk length too large"}, // could accept if we wanted
		{"10000000000000000", 0, "http chunk length too large"},
		{"00000000000000001", 0, "http chunk length too large"}, // could accept if we wanted
	}