wFMiddleware :: (Env -> Bool) -> (Env-> IO Response) ->   (Env -> IO Response)
wFMiddleware filter f = \ env ->  if filter env then hackMessageFlow env    else f env
wFMiddleware :: (Env -> Bool) -> (Env-> IO Response) ->   (Env -> IO Response)
wFMiddleware filter f = \ env ->  if filter env then hackMessageFlow env    else f env
wFMiddleware filter f = \ env ->  if filter env then hackMessageFlow env    else f env