public void AesEncryptionTool_CanEncryptAndDecryptInteger()
        {
            const int testinteger = 42;
            const string passphrase = "The quick brown fox jumps over the lazy dog.";

            AesEncryptionTool tool = new AesEncryptionTool();

            string ciphertext = tool.EncryptInt(testinteger, passphrase);
            Assert.AreNotEqual(testinteger, ciphertext);

            int decryptedInteger = tool.DecryptInt(ciphertext, passphrase);
            Assert.AreEqual(decryptedInteger, testinteger);
        }