assertFalse(rootFilter.includeAdd("x", x1));
Filter x1Filter = rootFilter.create("x", x1, x1);
assertNotNull(x1Filter);
NodeState y1 = x1.getChildNode("y");
assertFalse(x1Filter.includeAdd("y", y1));
Filter y1Filter = x1Filter.create("y", y1, y1);
assertNotNull(y1Filter);
NodeState x2 = y1.getChildNode("x");
assertFalse(y1Filter.includeAdd("x", x2));