public void testApplyFilter() {
Graph graph = new Graph();
graph.addNode(new DefaultNode("x"));
graph.addNode(new DefaultNode("y"));
graph.addNode(new DefaultNode("z"));
public void testApplyFilter() {
Graph graph = new Graph();
graph.addNode(new DefaultNode("x"));
graph.addNode(new DefaultNode("y"));
graph.addNode(new DefaultNode("z"));