Predicate<Object> predicate = Predicates.alwaysFalse();
    Map<String, Integer> filtered = Maps.filterEntries(unfiltered, predicate);
    assertTrue(filtered.isEmpty());
  }

  public void testFilteredEntriesWildCardEntryPredicate() {
    Map<String, Integer> unfiltered = createUnfiltered();
    unfiltered.put("cat", 3);
    unfiltered.put("dog", 2);
    unfiltered.put("horse", 5);