public UnmodifiableIterator<E> descendingIterator() {
    return forward.iterator();
  }

  @Override
  @GwtIncompatible("NavigableSet")
  ImmutableSortedSet<E> createDescendingSet() {
    throw new AssertionError("should never be called");
  }

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

  @Override
  @CheckForNull
  public E floor(E element) {

    setDefault(EndpointPair.class, EndpointPair.ordered("A", "B"));
  }

  @Override
  public void testNulls() throws Exception {
    try {
      super.testNulls();
    } catch (AssertionError e) {
      assertWithMessage("Method did not throw null pointer OR element not in graph exception.")
          .that(e)
          .hasCauseThat()
          .hasMessageThat()

     * be reached.
     */

    @Override
    protected A doForward(B b) {
      throw new AssertionError();
    }

    @Override
    protected B doBackward(A a) {
      throw new AssertionError();
    }

    @Override
    @CheckForNull
    A correctedDoForward(@CheckForNull B b) {
      return original.correctedDoBackward(b);
    }

            doStop();
            break;
          case STOPPING:
          case TERMINATED:
          case FAILED:
            // These cases are impossible due to the if statement above.
            throw new AssertionError("isStoppable is incorrectly implemented, saw: " + previous);
        }
      } catch (Throwable shutdownFailure) {
        restoreInterruptIfIsInterruptedException(shutdownFailure);
        notifyFailed(shutdownFailure);

      if (actualException instanceof InterruptedException) {
        return Outcome.INTERRUPT;
      } else {
        throw new AssertionError("unexpected exception", targetException);
      }
    } catch (IllegalAccessException e) {
      throw new AssertionError("unexpected exception", e);
    }
  }

  private void enterSatisfyGuardAndLeaveInCurrentThread() {
    monitor.enter();
    try {

    constructor.setAccessible(true); // accessibility check is too slow
    try {
      return constructor.newInstance();
    } catch (InstantiationException | IllegalAccessException impossible) {
      throw new AssertionError(impossible);
    } catch (InvocationTargetException e) {
      logger.log(Level.WARNING, "Exception while invoking default constructor.", e.getCause());
      return arbitraryConstantInstanceOrNull(type);
    }
  }

        @Override
        public Integer next(Integer value) {
          throw new AssertionError();
        }

        @Override
        public Integer previous(Integer value) {
          throw new AssertionError();
        }

        @Override
        public long distance(Integer start, Integer end) {
          throw new AssertionError();
        }
      };

  public void testCreate_noMin() {

        testToAscii(entry.input!!, entry.output, entry.comment)
      } catch (e: Throwable) {
        failure = e
      }

      if (entry.input in knownFailures) {
        if (failure == null) failures += AssertionError("known failure didn't fail: $entry")
      } else {
        if (failure != null) failures += failure
      }
    }

    if (failures.isNotEmpty()) {
      for (failure in failures) {
        println(failure)

  public UnmodifiableIterator<E> descendingIterator() {
    return forward.iterator();
  }

  @Override
  @GwtIncompatible("NavigableSet")
  ImmutableSortedSet<E> createDescendingSet() {
    throw new AssertionError("should never be called");
  }

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

  @Override
  @CheckForNull
  public E floor(E element) {

    }

    @Override
    Set<E> createElementSet() {
      return Sets.filter(unfiltered.elementSet(), predicate);
    }

    @Override
    Iterator<E> elementIterator() {
      throw new AssertionError("should never be called");
    }

    @Override
    Set<Entry<E>> createEntrySet() {
      return Sets.filter(
          unfiltered.entrySet(),
          new Predicate<Entry<E>>() {