public String generateResponseCode(long state)
      throws GeneralSecurityException {
    byte[] value = ByteBuffer.allocate(8).putLong(state).array();
    return generateResponseCode(value);
  }
@param state 8-byte integer value representing internal OTP state.
@return A decimal response code
@throws GeneralSecurityException If a JCE exception occur
java/com/google/android/apps/authenticator/otp/PasscodeGenerator.java