d concatenate the resulting lists.
--
-- >>> concatMapOf both (\x -> [x, x + 1]) (1,3)
-- [1,2,3,4]
--
-- @
-- 'concatMap' ≡ 'concatMapOf' 'folded'
-- @
--
-- @
-- 'concatMapOf' :: 'Getter' s a     -> (a -> [r]) -> s -> [r]
-- 'concatMapOf' :: 'Fold' s a       -> (a -> [r]) -> s -> [r]
-- 'concatMapOf' :: 'Lens'' s a      -> (a -> [r]) -> s -> [r]
-- 'concatMapOf' :: 'Iso'' s a       -> (a -> [r]) -> s -> [r]
-- 'concatMapOf' :: 'Traversal'' s a -> (a -> [r]) -> s -> [r]
-- @
concatMapOf :: Getting [r] s a -> (a -> [r]) -> s -> [r]
concatMapOf l ces = getConst #. l (Const #. ces)
{-# INLINE concatMapOf #-}

-- | Concatenate all of the lists targeted 
concatMapOf :: Getting [r] s a -> (a -> [r]) -> s -> [r]
concatMapOf l ces = getConst #. l (Const #. ces)
concatMapOf l ces = getConst #. l (Const #. ces)