liftIO :: IO a -> Mgr a
liftIO io = Mgr $ \s -> do
    a <- io
    return (a, s)
liftIO :: IO a -> Mgr a
liftIO io = Mgr $ \s -> do
    a <- io
    return (a, s)
liftIO io = Mgr $ \s -> do
    a <- io
    return (a, s)