// removed, since IdentityHashMap throws an exception when that occurs.
  @SuppressWarnings("IdentityHashMapBoxing") // explicitly testing IdentityHashMap
  public void testIdentityKeySetIteratorRemove() {
    BiMap<Integer, String> bimap =
        new AbstractBiMap<Integer, String>(
            new IdentityHashMap<Integer, String>(), new IdentityHashMap<String, Integer>()) {};
    bimap.put(1, "one");