Function cached_shortest_path_distance 

pub fn cached_shortest_path_distance(
    cache: &mut ShortestPathCache,
    graph: &DiGraph<NetelementSide, f64>,
    node_map: &HashMap<NetelementSide, NodeIndex>,
    from: &NetelementSide,
    to: &NetelementSide,
) -> Option<f64>

Look up or compute the shortest-path distance between two netelement sides, caching the result for future queries.