}
    return Collections.unmodifiableList(list);
  }

  /**
   * @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());
  }

    }
    return Collections.unmodifiableList(list);
  }

  /**
   * @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());
  }