Real-world example: Architecture components solved

- [Instructor] In previous videos we worked…a complex example using Dagger…in a real world application, and it didn't quite work,…but I promise that we could fix it.…The reason it didn't work is that…we couldn't yet tell Dagger to create…a key of type class out ViewModel.…We now know how to create more complex key types…using the @MapKey annotation.…In the last video, we used @MapKey…to create a new key annotation,…that created a mapkey from an enum.…

In this video, we'll see how to create…a map with a more complex key.…Again note, that the complete documentation…for the syntax for annotation classes…is available at kotlinlang.org.…I'm not going to write all this code out,…it's very similar to code we've seen before.…What I do want to point out, is that the @MapKey…annotation, when applied to an annotation class…with multiple parameters, must have…it's unwrap value parameter set false.…

The MapKey annotation parameter unwrap value…has to be set false.…This creates a new annotation, ComplexKey,…which we can use to create mapkeys in our module.…