code:     public void testPrivateKeyParsingSHA256()
          throws Exception
      {
          XMSSMTParameters params = new XMSSMTParameters(20, 10, new SHA256Digest());
          XMSSMT mt = new XMSSMT(params, new SecureRandom());
          mt.generateKeys();
          byte[] privateKey = mt.exportPrivateKey();
          byte[] publicKey = mt.exportPublicKey();
  
          mt.importState(privateKey, publicKey);
  
          assertTrue(Arrays.areEqual(privateKey, mt.exportPrivateKey()));
      }
  