graph.getNode("A").addAttribute("s", "foo bar");
graph.addNode("B");
graph.stepBegins(1);
graph.addEdge("AB", "A", "B", true);
graph.getEdge("AB").addAttribute("n", 1);
graph.stepBegins(2);
graph.addAttribute("b", true);
graph.getNode("B").addAttribute("c", 'X');
graph.getNode("B").addAttribute("d", 'Y');
graph.stepBegins(3);
graph.getNode("B").removeAttribute("c");