@MapFeature.Require({ALLOWS_NULL_KEYS, ALLOWS_NULL_VALUES})
  @CollectionSize.Require(absent = ZERO)
  public void testCreateWithNullKeyAndValueSupported() {
    Entry<K, V>[] entries = createSamplesArray();
    entries[getNullLocation()] = entry(null, null);
    resetMap(entries);
    expectContents(entries);
  }

  @MapFeature.Require(value = ALLOWS_NULL_KEYS, absent = REJECTS_DUPLICATES_AT_CREATION)
  @CollectionSize.Require(absent = {ZERO, ONE})

  }

  /**
   * @return a suitable location for a null element, to use when initializing containers for tests
   *     that involve a null element being present.
   */
  protected int getNullLocation() {
    return getNumElements() / 2;
  }

  protected MinimalCollection<E> createDisjointCollection() {
    return MinimalCollection.of(e3(), e4());
  }