include:
          - os: windows-latest
            java: 21
            root-pom: pom.xml
    runs-on: ${{ matrix.os }}
    env:
      ROOT_POM: ${{ matrix.root-pom }}
    steps:
      # Cancel any previous runs for the same branch that are still running.
      - name: 'Cancel previous runs'
        uses: styfle/cancel-workflow-action@85880fa0301c86cca9da44039ee3bb12d3bedbfa # 0.12.1
        with:

 * <p>The items in {@code elementsToInsert} will be repeated if {@code steps} is larger than the
 * number of provided elements.
 *
 * @author Chris Povirk
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public abstract class ListIteratorTester<E extends @Nullable Object>
    extends AbstractIteratorTester<E, ListIterator<E>> {
  protected ListIteratorTester(
      int steps,
      Iterable<E> elementsToInsert,

 * <p>The items in {@code elementsToInsert} will be repeated if {@code steps} is larger than the
 * number of provided elements.
 *
 * @author Chris Povirk
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public abstract class ListIteratorTester<E extends @Nullable Object>
    extends AbstractIteratorTester<E, ListIterator<E>> {
  protected ListIteratorTester(
      int steps,
      Iterable<E> elementsToInsert,

      return;
    }
    fail("Should have caught jdk6 bug in target iterator");
  }

  private static final int STEPS = 3;

  static class TesterThatCountsCalls extends IteratorTester<Integer> {
    TesterThatCountsCalls() {
      super(STEPS, MODIFIABLE, newArrayList(1), IteratorTester.KnownOrder.KNOWN_ORDER);
    }

    int numCallsToNewTargetIterator;
    int numCallsToVerify;

 * Iterator#remove} operations. This utility takes the brute-force approach of trying <i>all</i>
 * possible sequences of these operations, up to a given number of steps. So, if the caller
 * specifies to use <i>n</i> steps, a total of <i>3^n</i> tests are actually performed.
 *
 * <p>For instance, if <i>steps</i> is 5, one example sequence that will be tested is:
 *
 * <ol>
 *   <li>remove();
 *   <li>hasNext()
 *   <li>hasNext();
 *   <li>remove();

  }

  public void testPeekingIteratorBehavesLikeIteratorOnSingletonIterable() {
    actsLikeIteratorHelper(Collections.singletonList(new Object()));
  }

  // TODO(cpovirk): instead of skipping, use a smaller number of steps
  @GwtIncompatible // works but takes 5 minutes to run
  public void testPeekingIteratorBehavesLikeIteratorOnThreeElementIterable() {
    actsLikeIteratorHelper(Lists.newArrayList("A", "B", "C"));
  }

  AbstractIteratorTester(
      int steps,
      Iterable<E> elementsToInsertIterable,
      Iterable<? extends IteratorFeature> features,
      Iterable<E> expectedElements,
      KnownOrder knownOrder,
      int startIndex) {
    // periodically we should manually try (steps * 3 / 2) here; all tests but
    // one should still pass (testVerifyGetsCalled()).

      return;
    }
    fail("Should have caught jdk6 bug in target iterator");
  }

  private static final int STEPS = 3;

  static class TesterThatCountsCalls extends IteratorTester<Integer> {
    TesterThatCountsCalls() {
      super(STEPS, MODIFIABLE, newArrayList(1), IteratorTester.KnownOrder.KNOWN_ORDER);
    }

    int numCallsToNewTargetIterator;
    int numCallsToVerify;

 * Iterator#remove} operations. This utility takes the brute-force approach of trying <i>all</i>
 * possible sequences of these operations, up to a given number of steps. So, if the caller
 * specifies to use <i>n</i> steps, a total of <i>3^n</i> tests are actually performed.
 *
 * <p>For instance, if <i>steps</i> is 5, one example sequence that will be tested is:
 *
 * <ol>
 *   <li>remove();
 *   <li>hasNext()
 *   <li>hasNext();
 *   <li>remove();

    assertEquals(0, (int) mmHeap.peekLast());
  }

  private <T extends Comparable<T>> void runIterator(final List<T> values, int steps)
      throws Exception {
    IteratorTester<T> tester =
        new IteratorTester<T>(
            steps,
            IteratorFeature.MODIFIABLE,
            Lists.newLinkedList(values),
            IteratorTester.KnownOrder.UNKNOWN_ORDER) {