Inheritance of different models is a really powerful way of defining types because in reality are models and never nice key and value of different types. They always have complex items deeper down. That's really cool. And on top of these I guess we can add validation like you have the, you said the very optimistic validation like if in the friends with a different type of a model. If in the friends list it said one to comma Jane. Well, it's probably going to crash when it tries to convert Jane into an integer and say no no no this is wrong. But you could decide perhaps James a strange case but if you wanted the word one, oh any to somehow work you could