public void TestContainsKey()
        {
            IndexedList<string, SiteLink> list = new IndexedList<string, SiteLink>(siteLink => siteLink.SiteId) {
                new SiteLink("enwiki", "Foo")
            };

            Assert.True(list.ContainsKey("enwiki"));
            Assert.False(list.ContainsKey("xxwiki"));
        }