anchor.diff:  [source, haskell]
   ----
   {-# LANGUAGE OverloadedStrings #-}
  -import Network.Wai
  -import Network.Wai.Handler.Warp
  -import Network.HTTP.Types
  -import Data.Conduit
  -import Data.Conduit.Binary (sourceHandle)
  -import qualified Data.Conduit.List as CL
  -import Blaze.ByteString.Builder (fromByteString)
  -import System.IO (openFile, hClose, IOMode (ReadMode))
  +import           Blaze.ByteString.Builder (fromByteString)
  +import           Data.Conduit             (Flush (Chunk), ($=))
  +import           Data.Conduit.Binary      (sourceHandle)
  +import qualified Data.Conduit.List        as CL
  +import           Network.HTTP.Types       (status200)
  +import           Network.Wai              (Application, responseSourceBracket)
  +import           Network.Wai.Handler.Warp (run)
  +import           System.IO                (IOMode (ReadMode), hClose, openFile)
   
   main :: IO ()
   main = run 3000 app
  
positive.code: [source, haskell]
  ----
  {-# LANGUAGE OverloadedStrings #-}
  import Network.Wai
  import Network.Wai.Handler.Warp
  import Network.HTTP.Types
  
  main :: IO ()
  main = run 3000 app
  
negative.code: import           Control.Monad                      (forM_)
  import           Data.Monoid                        ((<>))
  import           Network.Wai                        (pathInfo)
  import           Yesod.Core                         (HandlerT, RenderRoute (..),
                                                       TypedContent, Yesod,
                                                       YesodDispatch (..), liftIO,
                                                       notFound, respondSource,
                                                       sendChunk, sendChunkBS,
                                                       sendChunkText, sendFlush,
                                                       warp, yesodRunner)
  
  -- | Our foundatation datatype.
  data App = App
  