Function shortest_path_route 

pub fn shortest_path_route(
    graph: &DiGraph<NetelementSide, f64>,
    node_map: &HashMap<NetelementSide, NodeIndex>,
    from: &NetelementSide,
    to: &NetelementSide,
) -> Option<Vec<NodeIndex>>

Return the sequence of graph nodes along the shortest direction-aware path.

Used by bridge insertion to recover intermediate netelements.