Let's see where we were...
The test for this looks like this:
When I run this I get the following error:
BookmarkCollectionFixture.RetrieveABookmarkNotInCollection : System.Collections.Generic.KeyNotFoundException : The given key was not present in the dictionary.
Unfortunately it does not return null like I want it to. I guess I will have to write some code. I need to modify the Indexer to check to see if the label is in the collection. If not it should return null. Here's the code:
Surveying the rest of the tests in the test list indicates that there is not much left so I should be able to finish up the task in the next couple of posts.