code: private void writeHeader() throws IOException {
      /* Write out the header */
      if (passwordBased) {
        macOutputStream.write(AES256JNCryptor.VERSION);
        macOutputStream.write(AES256Ciphertext.FLAG_PASSWORD);
        macOutputStream.write(encryptionSalt);
        macOutputStream.write(hmacSalt);
        macOutputStream.write(iv);
      } else {
        macOutputStream.write(AES256JNCryptor.VERSION);
        macOutputStream.write(0);
        macOutputStream.write(iv);
      }
    }
docs: Writes the header data to the output stream.
  
  @throws IOException