*
   * @return a value.
   * @throws UnsupportedOperationException if it's not possible to make a value that will not be
   *     found in the map.
   */
  protected abstract V getValueNotInPopulatedMap() throws UnsupportedOperationException;

  /**
   * Constructor that assigns {@code supportsIteratorRemove} the same value as {@code
   * supportsRemove}.
   */
  protected MapInterfaceTest(

   *
   * @return a value.
   * @throws UnsupportedOperationException if it's not possible to make a value that will not be
   *     found in the map.
   */
  protected abstract V getValueNotInPopulatedMap() throws UnsupportedOperationException;

  /**
   * Constructor that assigns {@code supportsIteratorRemove} the same value as {@code
   * supportsRemove}.
   */
  protected MapInterfaceTest(

  }

  @Override
  protected String getKeyNotInPopulatedMap() {
    return "a";
  }

  @Override
  protected Integer getValueNotInPopulatedMap() {
    return 4;
  }

  }

  @Override
  protected String getKeyNotInPopulatedMap() {
    return "a";
  }

  @Override
  protected Integer getValueNotInPopulatedMap() {
    return 1;
  }

  }

  @Override
  protected String getKeyNotInPopulatedMap() {
    return "a";
  }

  @Override
  protected Integer getValueNotInPopulatedMap() {
    return 1;
  }

    return ImmutableSortedMap.of("one", 1, "two", 2, "three", 3);
  }

  @Override
  protected String getKeyNotInPopulatedMap() {
    return "minus one";
  }

  @Override
  protected Integer getValueNotInPopulatedMap() {
    return -1;
  }

        colliders.e2(), 2,
        colliders.e3(), 3);
  }

  @Override
  protected Object getKeyNotInPopulatedMap() {
    return new Colliders().e4();
  }

  @Override
  protected Integer getValueNotInPopulatedMap() {
    return 4;
  }

    return SerializableTester.reserialize(map);
  }

  @Override
  protected String getKeyNotInPopulatedMap() {
    return "minus one";
  }

  @Override
  protected Integer getValueNotInPopulatedMap() {
    return -1;
  }

    return ImmutableBiMap.of("one", 1, "two", 2, "three", 3);
  }

  @Override
  protected String getKeyNotInPopulatedMap() {
    return "minus one";
  }

  @Override
  protected Integer getValueNotInPopulatedMap() {
    return -1;
  }

  }

  @Override
  protected String getKeyNotInPopulatedMap() {
    return "d";
  }

  @Override
  protected Integer getValueNotInPopulatedMap() {
    return 4;
  }