cons :: (Sized a) => a -> Node a -> Node a
cons a (Node s n) = Node (size a + s) (V.cons a n)
cons :: (Sized a) => a -> Node a -> Node a
cons a (Node s n) = Node (size a + s) (V.cons a n)
cons a (Node s n) = Node (size a + s) (V.cons a n)