Control.Monad.EitherK
data EitherK e a
runEitherK
toEitherK
eitherK
throwEitherK
catchEitherK
data EitherKT e m a
runEitherKT
toEitherKT
liftEitherK
lowerEitherK
throwEitherKT
catchEitherKT