EndpointPair.unordered(1, 1),
            EndpointPair.unordered(1, 3))
        .inOrder();
  }

  /**
   * Populates the graph with nodes and edges in a star shape with node `1` in the middle.
   *
   * <p>Note that the edges are added in a shuffled order to properly test the effect of the
   * insertion order.
   */
  private void populateTShapedGraph() {
    putEdge(2, 1);

            EndpointPair.ordered(1, 1),
            EndpointPair.ordered(1, 3),
            EndpointPair.ordered(1, 2))
        .inOrder();
  }

  /**
   * Populates the graph with nodes and edges in a star shape with node `1` in the middle.
   *
   * <p>Note that the edges are added in a shuffled order to properly test the effect of the
   * insertion order.
   */
  private void populateStarShapedGraph() {
    putEdge(2, 1);

            EndpointPair.ordered(1, 1),
            EndpointPair.ordered(1, 3),
            EndpointPair.ordered(1, 2))
        .inOrder();
  }

  /**
   * Populates the graph with nodes and edges in a star shape with node `1` in the middle.
   *
   * <p>Note that the edges are added in a shuffled order to properly test the effect of the
   * insertion order.
   */
  private void populateStarShapedGraph() {
    putEdge(2, 1);

            EndpointPair.unordered(1, 1),
            EndpointPair.unordered(1, 3))
        .inOrder();
  }

  /**
   * Populates the graph with nodes and edges in a star shape with node `1` in the middle.
   *
   * <p>Note that the edges are added in a shuffled order to properly test the effect of the
   * insertion order.
   */
  private void populateTShapedGraph() {
    putEdge(2, 1);

   * |      |
   * e ---- c ---- f
   * }</pre>
   */
  private static final SuccessorsFunction<Character> JAVADOC_GRAPH =
      createUndirectedGraph("ba", "ad", "be", "ac", "ec", "cf");

  /**
   * A diamond shaped directed graph (arrows going down):
   *
   * <pre>{@code
   *   a
   *  / \
   * b   c
   *  \ /
   *   d
   * }</pre>
   */
  private static final SuccessorsFunction<Character> DIAMOND_GRAPH =

        makeMap(createMapMaker().concurrencyLevel(concurrencyLevel));
    assertThat(map.segments).hasLength(segmentCount);
  }

  public void testSetInitialCapacity() {
    // share capacity over each segment, then round up to the nearest power of two

    checkInitialCapacity(1, 0, 1);
    checkInitialCapacity(1, 1, 1);
    checkInitialCapacity(1, 2, 2);
    checkInitialCapacity(1, 3, 4);

        makeMap(createMapMaker().concurrencyLevel(concurrencyLevel));
    assertThat(map.segments).hasLength(segmentCount);
  }

  public void testSetInitialCapacity() {
    // share capacity over each segment, then round up to the nearest power of two

    checkInitialCapacity(1, 0, 1);
    checkInitialCapacity(1, 1, 1);
    checkInitialCapacity(1, 2, 2);
    checkInitialCapacity(1, 3, 4);

      // been acquired. For unordered locks, aboutToAcquire() ensures this by
      // checking isAcquiredByCurrentThread(). For ordered locks, however, this
      // can happen because multiple locks may share the same LockGraphNode. In
      // this situation, throw an IllegalStateException as defined by contract
      // described in the documentation of WithExplicitOrdering.
      Preconditions.checkState(

 */
// TODO: Descriptive assertion messages, with hints as to probable fixes.
// TODO: Add another constructor parameter indicating whether the class under test is ordered, and
// check the order if so.
// TODO: Refactor to share code with SetTestBuilder etc.
@GwtCompatible
@ElementTypesAreNonnullByDefault
public abstract class MapInterfaceTest<K extends @Nullable Object, V extends @Nullable Object>
    extends TestCase {

   * scattered in memory and thus don't interfere much with each
   * other. But Atomic objects residing in arrays will tend to be
   * placed adjacent to each other, and so will most often share
   * cache lines (with a huge negative performance impact) without
   * this precaution.
   *
   * In part because Cells are relatively large, we avoid creating