I've put a `UICollectionView` in the *header* of my table, but when I test it all I see is a black rectangle where my *collection* should be. What do I have to do to be able to see it? I did some research and found a method called `viewForHeaderInSection`, but I haven't found any explanation for it so I don't even know if that is what I need or what to do with it.

An additional question would be where do I put the related methods for the *collection*? (a new file?)

If it's important, this is on an IPad screen.