Ah I see I misread your comment. You're right, Cujo also shouldn't have validated. In a previous version of the post `neutered` was nullable and `age` was opti

Ah I see I misread your comment. You're right, Cujo also shouldn't have validated. In a previous version of the post `neutered` was nullable and `age` was optional, but I decided to save the discussion of nullables/optional until later so I changed it. Good catch!!