pub fn diameter<N, E, Ix>(graph: &Graph<N, E, Ix>) -> Option<f64>where N: Node + Clone + Hash + Eq + Debug, E: EdgeWeight + Into<f64> + Clone + Zero + One + PartialOrd + Debug + Copy + Default, Ix: IndexType,
Computes the diameter of a graph
The diameter is the maximum shortest path distance between any two nodes in the graph. Returns None if the graph is disconnected.