when(backingMap.get(KEY)).thenReturn(current);

    assertEquals(countToRemove + countRemaining, multiset.remove(KEY, countToRemove));
    assertEquals(countRemaining, current.get());
  }

  public void testRemove_noneRemaining() {
    int countToRemove = 30;
    AtomicInteger current = new AtomicInteger(countToRemove);

    when(backingMap.get(KEY)).thenReturn(current);