#!/usr/bin/perl -w
use Graph::Directed;
use Graph::BFS;

$G = new Graph::Directed;

$G = $G->add_edge("dave","mark");
$G = $G->add_edge("mark","paul");
$G = $G->add_edge("paul","john");

$set = Graph::BFS->new($G,%param);

# or should I use $G = $G->SSSP_Dijkstra(); here ?