public void AddIfNotContainsKeyTest2NullCheck()
        {
            // ReSharper disable once AssignNullToNotNullAttribute
            Action test = () => Extensions.AddIfNotContainsKey(null, new Object(), () => new Object());

            test.ShouldThrow <NullReferenceException>();
        }
        public void AddIfNotContainsKey1TestNullCheck1()
        {
            // ReSharper disable once AssignNullToNotNullAttribute
            Action test = () => Extensions.AddIfNotContainsKey(null, new KeyValuePair <Object, Object>());

            test.ShouldThrow <ArgumentNullException>();
        }