         DirectedMultigraph<String> g = new DirectedMultigraph<String>();         assertTrue(g.add(new SimpleDirectedTypedEdge<String>("type-0", 0, 0)));         assertTrue(g.add(new SimpleDirectedTypedEdge<String>("type-0", 0, 0)));         assertTrue(g.add(new SimpleDirectedTypedEdge<String>("type-0", 0, 0)));         assertTrue(g.add(new SimpleDirectedTypedEdge<String>("type-0", 0, 0)));         assertTrue(g.add(new SimpleDirectedTypedEdge<String>("type-0", 0, 0)));                   Set<Integer> verts = new HashSet<Integer>();         