protected void setUp() {
    backingMap = mock(ConcurrentMap.class);
    when(backingMap.isEmpty()).thenReturn(true);

    multiset = ConcurrentHashMultiset.create(backingMap);
  }

  public void testCount_elementPresent() {
    int COUNT = 12;
    when(backingMap.get(KEY)).thenReturn(new AtomicInteger(COUNT));

    assertEquals(COUNT, multiset.count(KEY));
  }

  public void testCount_elementAbsent() {