it.next();
      it.remove();
      mutations++;
    }
    assertTrue(multiset.isEmpty());
    assertEquals(3, mutations);
  }

  public void testSetCount_basic() {
    int initialCount = 20;
    int countToSet = 40;
    AtomicInteger current = new AtomicInteger(initialCount);

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