map = obs.getObservations();
assertEquals("Check list #1", ((List) map.get("list")).size(), 1);
assertEquals("Check modification #1 (" + map.get("modifications") + ")", ((Integer) map.get("modifications")).intValue(), 1);
fs.foo();
map = obs.getObservations();
assertEquals("Check list #1", ((List) map.get("list")).size(), 1);
assertEquals("Check modification #2", ((Integer) map.get("modifications")).intValue(), 2);