let edge_attributes e =
let attr = [] in
let attr = (`Label (String.escaped (PE.edge_txt e)))::attr in
let attr =
if is_back_edge e then (`Constraints false)::(`Style `Bold)::attr
else attr
in
let attr = match !(CFG.E.label e) with
| Ethen | EbackThen -> (`Color 0x00FF00)::attr
| Eelse | EbackElse -> (`Color 0xFF0000)::attr
| _ -> attr
in
attr