// synchronized collections can be safely copied.
    SortedMultiset<String> toCopy = mock(SortedMultiset.class);
    TestHashSet<Entry<String>> entrySet = new TestHashSet<>();
    when((Comparator<Comparable<String>>) toCopy.comparator())
        .thenReturn(Ordering.<Comparable<String>>natural());
    when(toCopy.entrySet()).thenReturn(entrySet);

  }

  public void testSet() {
    assertFreshInstance(new TypeToken<Set<String>>() {});
    assertNotInstantiable(new TypeToken<Set<EmptyEnum>>() {});
  }

  public void testHashSet() {
    assertFreshInstance(new TypeToken<HashSet<String>>() {});
  }

  public void testLinkedHashSet() {
    assertFreshInstance(new TypeToken<LinkedHashSet<String>>() {});
  }