deleteEdges :: [EdgeId] -> StGNG a ()
deleteEdges eids = do
    gng <- State.get
    State.modify (&edges .~ foldl' (flip Map.delete) (gng^.edges) eids)
deleteEdges :: [EdgeId] -> StGNG a ()
deleteEdges eids = do
    gng <- State.get
    State.modify (&edges .~ foldl' (flip Map.delete) (gng^.edges) eids)
deleteEdges eids = do
    gng <- State.get
    State.modify (&edges .~ foldl' (flip Map.delete) (gng^.edges) eids)