{-# WARNING
    test
    , foo
    [ "These are bad functions"
    , "Really bad!"
    ]
    #-}
test :: IO ()
test = pure ()

instance
    {-# WARNING "Don't use" #-}
    Show G1 where
    show = "G1"

deriving instance
        {-# WARNING "to be removed" #-}
    Eq G2