visualize' :: NetBuilder () -> IO ()
visualize' g = do
  (file, handle) <- openTempFile "/tmp" "graph.png"
  hClose handle
  f <- parse g & visualize & png file
  _ <- system $ printf "open %s &" f
  return ()
visualize' :: NetBuilder () -> IO ()
visualize' g = do
  (file, handle) <- openTempFile "/tmp" "graph.png"
  hClose handle
  f <- parse g & visualize & png file
  _ <- system $ printf "open %s &" f
  return ()
visualize' g = do
  (file, handle) <- openTempFile "/tmp" "graph.png"
  hClose handle
  f <- parse g & visualize & png file
  _ <- system $ printf "open %s &" f
  return ()