-- | An iso which witnesses that tuples can be flipped without
-- losing any information
-- dimap :: (a1 -> a) -> (b -> b1) -> (a -> b) -> (a1 -> b1)
-- >_> (ba -> f ba) ->> (ab -> f ab)
_flip :: Iso (a, b) (a, b) (b, a) (b, a)
_flip = dimap flipT (flipT <$>)
  where flipT (a, b) = (b, a)
--
_flip :: Iso (a, b) (a, b) (b, a) (b, a)
_flip = dimap flipT (flipT <$>)
  where flipT (a, b) = (b, a)
--
_flip = dimap flipT (flipT <$>)
  where flipT (a, b) = (b, a)
--