Is Misty ((->) t) banana right?

gistfile1.hs

class Misty m where
  banana :: (a -> m b) -> m a -> m b
  unicorn :: a -> m a
  -- Exercise 6
  -- Relative Difficulty: 3
  -- (use banana and/or unicorn)
  furry' :: (a -> b) -> m a -> m b
  furry' = banana . (unicorn .)
  
instance Misty ((->) t) where
  banana f m = \t → f (m t) t
  unicorn a = \t → a