nestedErrMapK :: IO ()
nestedErrMapK = assertEqual "Failed to error on mapK'ed dups across blocks"
                (Left ['B'])
                (runMap $ do
                    mapK succ $ mkMapABC (#!)
                    mapK succ $ mkMapAEF (#!)
                )
nestedErrMapK :: IO ()
nestedErrMapK = assertEqual "Failed to error on mapK'ed dups across blocks"
                (Left ['B'])
                (runMap $ do
                    mapK succ $ mkMapABC (#!)
                    mapK succ $ mkMapAEF (#!)
                )
nestedErrMapK = assertEqual "Failed to error on mapK'ed dups across blocks"
                (Left ['B'])
                (runMap $ do
                    mapK succ $ mkMapABC (#!)
                    mapK succ $ mkMapAEF (#!)
                )