public void CountryRepository_AddValue()
        {
            var repo = new CountryRepository();

            var key         = "AAA";
            var countryInfo = new CountryInfo
            {
                CountryCode  = "AAA",
                CountryName  = "Added Fake Country",
                BaseCurrency = "AAA"
            };

            repo.AddValue(key, countryInfo);

            var value       = repo.GetValue <CountryInfo>(key);
            var containsKey = repo.ContainsKey(key);

            Assert.IsNotNull(value);
            Assert.IsTrue(containsKey);
            Assert.AreEqual("AAA", value.CountryCode);
        }