{-# LANGUAGE TypeFamilies #-}

class Foo a where type FooBar a = Int

-- | Something.
class Bar a where
    -- Define bar
    type
        BarBar a =
            BarBaz a

    -- Define baz
    type
        BarBaz
            a =
            BarBar -- Middle comment
                a

class Baz a where
    type
        BazBar
            a

    type
        BazBar a =
            Bar a
