Haskell: Animate a SVG graphic

I have an SVG file, that I would like to animate with Haskell Reanimate:

I would like to e.g. make the arrows appear little by little. How to do that? I read the file with:

anim :: IO ()
anim = do
  doc <- loadSvgFile "test.svg" 
  tree <- case doc of
    Nothing  -> error "Malformed svg"
    Just svg -> return $ embedDocument svg
  reanimate $ addStatic (mkBackground "cyan") $ staticFrame 1 $ tree

This works well. However, I'm not sure where to go from here. How to animate the arrows?

Thanks a lot