Easy rust realization of generic graph
Data structure that represent generic vertices and undirected connections
``` let verts = vec![0, 1, 2, 3, 4, 10]; let conns = vec![(0, 1), (1, 2), (2, 3), (3, 4), (10, 0), (4, 10)];
let graph = Graph::fromdata(verts.intoiter(), conns.intoiter()); asserteq!(verts.len(), graph.len());
let newvertex = 15; assert!(graph.addvertex(newvertex)); assert!(graph.contains(&newvertex));
graph.addedge(&1, &4); assert!(graph.isconnected(&1, &4)); assert!(graph.is_connected(&4, &1)); ```