*
   * @param index the index of the stripe to return; must be in {@code [0...size())}
   * @return the stripe at the specified index
   */
  public abstract L getAt(int index);

  /**
   * Returns the index to which the given key is mapped, so that getAt(indexFor(key)) == get(key).
   */
  abstract int indexFor(Object key);

  /** Returns the total number of stripes in this instance. */
  public abstract int size();

    Set<Object> observed = Sets.newIdentityHashSet(); // for the sake of weakly referenced locks.
    // this gets the stripes with #getAt(index)
    for (int i = 0; i < striped.size(); i++) {
      Object object = striped.getAt(i);
      assertThat(object).isNotNull();
      assertSame(object, striped.getAt(i)); // idempotent
      observed.add(object);
    }
    assertTrue("All stripes observed", observed.size() == striped.size());

    Set<Object> observed = Sets.newIdentityHashSet(); // for the sake of weakly referenced locks.
    // this gets the stripes with #getAt(index)
    for (int i = 0; i < striped.size(); i++) {
      Object object = striped.getAt(i);
      assertThat(object).isNotNull();
      assertSame(object, striped.getAt(i)); // idempotent
      observed.add(object);
    }
    assertTrue("All stripes observed", observed.size() == striped.size());

  @Footprint
  Object sizeOfPopulatedStriped() {
    locks.clear();
    Striped<Lock> striped = impl.get(numStripes);
    for (int i : stripes) {
      locks.add(striped.getAt(i));
    }
    return striped;
  }

  @Benchmark
  long timeConstruct(long reps) {
    long rvalue = 0;
    int numStripesLocal = numStripes;
    Impl implLocal = impl;

  @Footprint
  Object sizeOfPopulatedStriped() {
    locks.clear();
    Striped<Lock> striped = impl.get(numStripes);
    for (int i : stripes) {
      locks.add(striped.getAt(i));
    }
    return striped;
  }

  @Benchmark
  long timeConstruct(long reps) {
    long rvalue = 0;
    int numStripesLocal = numStripes;
    Impl implLocal = impl;