If you use Core Data in your apps, you might be aware that the larger and more complicated your set up becomes, the harder it is to debug. It's at this point where you might start to get frustrated with Core Data and its black-box kind of implementation. You might think that you simply have to trust that Core Data will do the ideal thing for your app. Furthermore, you might have a set up with multiple managed object contexts, each confined to its own thread. And when your app crashes sometimes, you think it's related to Core Data in...