public NavigableSet<E> headSet(E toElement, boolean inclusive) {
    return new SafeTreeSet<>(delegate.headSet(checkValid(toElement), inclusive));
  }

  @Override
  public @Nullable E higher(E e) {
    return delegate.higher(checkValid(e));
  }

  @Override
  public boolean isEmpty() {
    return delegate.isEmpty();
  }

  @Override
  public Iterator<E> iterator() {
    return delegate.iterator();

  @CheckForNull
  public E ceiling(E element) {
    int index = tailIndex(element, true);
    return (index == size()) ? null : elements.get(index);
  }

  @Override
  @CheckForNull
  public E higher(E element) {
    int index = tailIndex(element, false);
    return (index == size()) ? null : elements.get(index);
  }

  @Override
  ImmutableSortedSet<E> headSetImpl(E toElement, boolean inclusive) {

  @CheckForNull
  public E lower(E element) {
    return forward.higher(element);
  }

  @Override
  @CheckForNull
  public E floor(E element) {
    return forward.ceiling(element);
  }

  @Override
  @CheckForNull
  public E ceiling(E element) {
    return forward.floor(element);
  }

  @Override
  @CheckForNull
  public E higher(E element) {
    return forward.lower(element);
  }

      nextHigherIndex = i;
    }
    switch (absentBehavior) {
      case NEXT_LOWER:
        assertEquals(nextHigherIndex - 1, answer);
        return;
      case NEXT_HIGHER:
        assertEquals(nextHigherIndex, answer);
        return;
      case INVERTED_INSERTION_INDEX:
        assertEquals(-1 - nextHigherIndex, answer);
        return;
      default:

      thrownReflectionFailure = reflectionFailure;
      helper = new SynchronizedAtomicHelper();
    }
    ATOMIC_HELPER = helper;
    // Log after all static init is finished; if an installed logger uses any Futures methods, it
    // shouldn't break in cases where reflection is missing/broken.
    if (thrownReflectionFailure != null) {
      log.get().log(Level.SEVERE, "SafeAtomicHelper is broken!", thrownReflectionFailure);

 *
 * @author Nishant Thakkar
 * @author Sven Mawson
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public final class ExecutionList {
  /** Logger to log exceptions caught when running runnables. */
  private static final LazyLogger log = new LazyLogger(ExecutionList.class);

  /**

        B extends PerCollectionSizeTestSuiteBuilder<B, G, T, E>,
        G extends TestContainerGenerator<T, E>,
        T,
        E>
    extends FeatureSpecificTestSuiteBuilder<B, G> {
  private static final Logger logger =
      Logger.getLogger(PerCollectionSizeTestSuiteBuilder.class.getName());

  /** Creates a runnable JUnit test suite based on the criteria already given. */
  @Override
  public TestSuite createTestSuite() {

  @CheckForNull
  public E lower(E element) {
    return forward.higher(element);
  }

  @Override
  @CheckForNull
  public E floor(E element) {
    return forward.ceiling(element);
  }

  @Override
  @CheckForNull
  public E ceiling(E element) {
    return forward.floor(element);
  }

  @Override
  @CheckForNull
  public E higher(E element) {
    return forward.lower(element);
  }

     * That may introduce an extra class for each lambda (currently a dozen).
     */
    Logger local = logger;
    if (local != null) {
      return local;
    }
    synchronized (this) {
      local = logger;
      if (local != null) {
        return local;
      }
      return logger = Logger.getLogger(loggerName);
    }
  }

        B extends PerCollectionSizeTestSuiteBuilder<B, G, T, E>,
        G extends TestContainerGenerator<T, E>,
        T,
        E>
    extends FeatureSpecificTestSuiteBuilder<B, G> {
  private static final Logger logger =
      Logger.getLogger(PerCollectionSizeTestSuiteBuilder.class.getName());

  /** Creates a runnable JUnit test suite based on the criteria already given. */
  @Override
  public TestSuite createTestSuite() {