Cat is a variant of discriminated unions that map 'kind' to different tags: it keeps 'cat' from Pet, so these unions cannot decode it: Animal ('feline').
Dog is a variant of discriminated unions that map 'kind' to different tags: it keeps 'dog' from Pet, so these unions cannot decode it: Animal ('canine').
Fish is a variant of discriminated unions that map 'kind' to different tags: it keeps 'Fish' from Pond, so these unions cannot decode it: Sea ('fin').
Circle is a variant of discriminated unions that map 'shape' to different tags: it keeps 'disc' from Drawing, so these unions cannot decode it: Figure ('circle', 'round').
Eel is a variant of discriminated unions that map 'kind' to different tags: it keeps 'swim' from Ocean, so these unions cannot decode it: Lake ('Eel').
Ring is a variant of discriminated unions that map 'shape' to different tags: it keeps 'band', 'loop' from Emblem, so these unions cannot decode it: Badge ('ring', 'hoop').
