public NavigableSet<E> elementSet() {
    return delegate().elementSet();
  }

  /**
   * A sensible implementation of {@link SortedMultiset#elementSet} in terms of the following
   * methods: {@link SortedMultiset#clear}, {@link SortedMultiset#comparator}, {@link
   * SortedMultiset#contains}, {@link SortedMultiset#containsAll}, {@link SortedMultiset#count},
   * {@link SortedMultiset#firstEntry} {@link SortedMultiset#headMultiset}, {@link

    }
  }

  @Override
  public void clear() {
    if (needsAllocArrays()) {
      return;
    }
    incrementModCount();
    Set<E> delegate = delegateOrNull();
    if (delegate != null) {
      metadata =
          Ints.constrainToRange(size(), CompactHashing.DEFAULT_SIZE, CompactHashing.MAX_SIZE);
      delegate.clear(); // invalidate any iterators left over!
      table = null;

    }

    @Override
    public void clear() {
      forwardList.clear();
    }

    @Override
    @ParametricNullness
    public T remove(int index) {
      return forwardList.remove(reverseIndex(index));
    }

    @Override
    protected void removeRange(int fromIndex, int toIndex) {
      subList(fromIndex, toIndex).clear();
    }

    @Override
    @ParametricNullness

    assertThat(multimap.get("foo")).containsExactly(1, 2, 3, 4, 5).inOrder();
    List<Integer> sublist = list.subList(0, 5);
    assertThat(sublist).containsExactly(1, 2, 3, 4, 5).inOrder();

    sublist.clear();
    assertTrue(sublist.isEmpty());
    multimap.put("foo", 6);

    assertThrows(ConcurrentModificationException.class, () -> sublist.isEmpty());
  }

  public void testCreateFromMultimap() {

    return true;
  }

  @Override
  @CanIgnoreReturnValue
  public boolean addAll(Collection<? extends E> collection) {
    int size = collection.size();
    if (size >= maxSize) {
      clear();
      return Iterables.addAll(this, Iterables.skip(collection, size - maxSize));
    }
    return standardAddAll(collection);
  }

  @Override

          extras = new ArrayList<>();
        }
        extras.add(other.element);
        extras.addAll(other.extras);
        if (extras.size() > MAX_EXTRAS) {
          extras.subList(MAX_EXTRAS, extras.size()).clear();
          throw multiples(true);
        }
        return this;
      }
    }

    @IgnoreJRERequirement // see enclosing class (whose annotation Animal Sniffer ignores here...)

        private String fieldName;

        private final StringBuilder buffer = new StringBuilder(1000);

        @Override
        public void startDocument() {
            dataMap.clear();
        }

        @Override
        public void startElement(final String uri, final String localName, final String qName, final Attributes attributes) {
            if ("field".equals(qName)) {

    if (oldCount == 0 && count > 0) {
      distinctElements++;
    } else if (oldCount > 0 && count == 0) {
      distinctElements--;
    }
    return oldCount;
  }

  @Override
  public void clear() {
    Arrays.fill(counts, 0);
    size = 0;
    distinctElements = 0;
  }

  abstract class Itr<T> implements Iterator<T> {
    int index = 0;
    int toRemove = -1;

                    if (log.isDebugEnabled()) {
                        log.debug("Reading " + tc.getConfig().getLmHostsFileName());
                    }
                    this.lastModified = lm;
                    this.table.clear();
                    try (FileReader r = new FileReader(f)) {
                        populate(r, tc);
                    }
                }
                result = this.table.get(name);
            }

     */
    @Execute
    public JsonResponse<ApiResult> delete$all() {
        try {
            failureUrlService.deleteAll(failureUrlPager);
            failureUrlPager.clear();
            saveInfo(messages -> messages.addSuccessFailureUrlDeleteAll(GLOBAL));
        } catch (final Exception e) {
            logger.warn("Failed to process a request.", e);