let get_test_edges cfg v =
match succ_e cfg v with
| [e1; e2] ->
begin match (edge_type e1), (edge_type e2) with
| (Ethen|EbackThen), (Eelse|EbackElse) -> e1, e2
| (Eelse|EbackElse), (Ethen|EbackThen) -> e2, e1
| _, (Eelse|EbackElse) -> Wp_parameters.fatal
"[cfg] test node with invalid edges %a" pp_edge e1
| _, _ -> Wp_parameters.fatal
"[cfg] test node with invalid edges %a" pp_edge e2
end
| _ -> raise (Invalid_argument "[cfg:get_test_edges] not a test")