$ do state ← readTVar $ niState ni
when (state > DecidingHeader)
$ fail "Too late to declare the response status."
- setResponseStatus ni sc
+ res ← readTVar $ niResponse ni
+ writeTVar (niResponse ni) $ setStatusCode sc res
-- |@'setHeader' name value@ declares the value of the response header
-- @name@ as @value@. Note that this function is not intended to be