Set<String> presentAsSet = Optional.of("a").asSet();
    assertThrows(UnsupportedOperationException.class, () -> presentAsSet.add("b"));
  }

  public void testAsSet_absentIsImmutable() {
    Set<Object> absentAsSet = Optional.absent().asSet();
    assertThrows(UnsupportedOperationException.class, () -> absentAsSet.add("foo"));
  }

  public void testTransform_absent() {

    return delegate().lastEntry();
  }

  @Override
  public @Nullable Entry<E> pollFirstEntry() {
    throw new UnsupportedOperationException();
  }

  @Override
  public @Nullable Entry<E> pollLastEntry() {
    throw new UnsupportedOperationException();
  }

  @Override
  public SortedMultiset<E> headMultiset(@ParametricNullness E upperBound, BoundType boundType) {

    } catch (UnsupportedOperationException tolerated) {
    }
    expectUnchanged();
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testPut_unsupportedPresentDifferentValue() {
    assertThrows(UnsupportedOperationException.class, () -> getMap().put(k0(), v3()));
    expectUnchanged();
  }

   *
   * @throws UnsupportedOperationException always
   * @deprecated Unsupported operation.
   */
  @CanIgnoreReturnValue
  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  public final ImmutableList<V> removeAll(@Nullable Object key) {
    throw new UnsupportedOperationException();
  }

  /**

          .put(TimeoutException.class, e -> e instanceof TimeoutException)
          .put(UnsupportedCharsetException.class, e -> e instanceof UnsupportedCharsetException)
          .put(UnsupportedOperationException.class, e -> e instanceof UnsupportedOperationException)
          .put(VerifyException.class, e -> e instanceof VerifyException)
          .putAll(PlatformSpecificExceptionBatch.PLATFORM.exceptions())
          .buildOrThrow();

    List<V> values = singletonList(v3());
    assertThrows(UnsupportedOperationException.class, () -> multimap().replaceValues(k0(), values));
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  public void testReplaceValuesPutNotSupported() {
    List<V> values = singletonList(v3());
    assertThrows(UnsupportedOperationException.class, () -> multimap().replaceValues(k0(), values));
  }

          .put(TimeoutException.class, e -> e instanceof TimeoutException)
          .put(UnsupportedCharsetException.class, e -> e instanceof UnsupportedCharsetException)
          .put(UnsupportedOperationException.class, e -> e instanceof UnsupportedOperationException)
          .put(VerifyException.class, e -> e instanceof VerifyException)
          .putAll(PlatformSpecificExceptionBatch.PLATFORM.exceptions())
          .buildOrThrow();

                    handlerStack.addFirst(handler);
                    tagStack.addFirst(name);
                    return;
                }
            }
            throw new UnsupportedOperationException();
        }

        @Override
        void onEndHtmlElement(String name) {
            if (!tagStack.isEmpty() && tagStack.getFirst().equals(name)) {
                tagStack.removeFirst();

      Runnable command, long initialDelay, long period, TimeUnit unit) {
    throw new UnsupportedOperationException("scheduleAtFixedRate is not supported.");
  }

  @Override
  public ListenableScheduledFuture<?> scheduleWithFixedDelay(
      Runnable command, long initialDelay, long delay, TimeUnit unit) {
    throw new UnsupportedOperationException("scheduleWithFixedDelay is not supported.");
  }

    expectUnchanged();
  }

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
  public void testRemoveUnsupported() {
    assertThrows(UnsupportedOperationException.class, () -> getMultiset().remove(e0(), 2));
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testRemoveZeroNoOp() {
    int originalCount = getMultiset().count(e0());