finder.clear();
finder.add(new HashSet<String>(Arrays.asList("A", "X")));
finder.add(new HashSet<String>(Arrays.asList("B", "X")));
finder.clear();
finder.add(new HashSet<String>(Arrays.asList("A", "B", "C")));
finder.add(new HashSet<String>(Arrays.asList("X", "Y", "Z")));