} else {
      assertThrows(
          UnsupportedOperationException.class, () -> entrySet.remove(entrySet.iterator().next()));
    }
    assertInvariants(map);
  }

  public void testEntrySetRemoveMissingKey() {
    Map<K, V> map;
    K key;
    try {
      map = makeEitherMap();
      key = getKeyNotInPopulatedMap();
    } catch (UnsupportedOperationException e) {
      return;
    }