testGD :: (Int, Int) -> Drawing -> IO ()
testGD (w,h) d = do image <- drawGD (w,h) d
                    bs <- savePngByteString image
                    BS.putStrLn bs
testGD :: (Int, Int) -> Drawing -> IO ()
testGD (w,h) d = do image <- drawGD (w,h) d
                    bs <- savePngByteString image
                    BS.putStrLn bs
testGD (w,h) d = do image <- drawGD (w,h) d
                    bs <- savePngByteString image
                    BS.putStrLn bs