BreadthFirstSearch<Integer> bfs = new BreadthFirstSearch<>();
SimpleTree tree = new SimpleTree(4);
tree.setTreeRoot(0);
tree.addEdge(new AnnotatedEdge<Integer, Double, Object>(1, 0));
tree.addEdge(new AnnotatedEdge<Integer, Double, Object>(2, 0));
tree.addEdge(new AnnotatedEdge<Integer, Double, Object>(3, 0));
ListCallBack lcb = new ListCallBack();
bfs.traverse(tree, lcb);
assertEquals(4, lcb.getVisited().size());
for (int i = 0; i < 4; i++) {
assertEquals(i, lcb.getVisited().get(i).intValue());