@CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testRemove_occurrences_present() {
    assertEquals(
        "multiset.remove(present, 2) didn't return the old count",
        1,
        getMultiset().remove(e0(), 2));
    assertFalse(
        "multiset contains present after multiset.remove(present, 2)",
        getMultiset().contains(e0()));
    assertEquals(0, getMultiset().count(e0()));
  }

      fail();
    } catch (IllegalStateException expected) {
    }
  }

  public void testGet_present() {
    assertEquals("training", Optional.of("training").get());
  }

  @SuppressWarnings("OptionalOfRedundantMethod") // Unit tests for Optional
  public void testOr_T_present() {
    assertEquals("a", Optional.of("a").or("default"));
  }

  public void testOr_T_absent() {

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testRemove_occurrences_present() {
    assertEquals(
        "multiset.remove(present, 2) didn't return the old count",
        1,
        getMultiset().remove(e0(), 2));
    assertFalse(
        "multiset contains present after multiset.remove(present, 2)",
        getMultiset().contains(e0()));
    assertEquals(0, getMultiset().count(e0()));
  }

 * might be absent" as two distinct types in your program, which can aid clarity.
 *
 * <p>Some uses of this class include
 *
 * <ul>
 *   <li>As a method return type, as an alternative to returning {@code null} to indicate that no
 *       value was available
 *   <li>To distinguish between "unknown" (for example, not present in a map) and "known to have no

      optional.get();
      fail();
    } catch (IllegalStateException expected) {
    }
  }

  public void testGet_present() {
    assertEquals("training", Optional.of("training").get());
  }

  @SuppressWarnings("OptionalOfRedundantMethod") // Unit tests for Optional
  public void testOr_T_present() {
    assertEquals("a", Optional.of("a").or("default"));
  }

  public void testOr_T_absent() {

                }));
    expectAdded(entry(null, v3()));
  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testMergePresent() {
    assertEquals(
        "Map.merge(present, value, function) should return function result",
        v4(),
        getMap()
            .merge(
                k0(),
                v3(),
                (oldV, newV) -> {

  /** Return type from "contains the following elements" assertions. */
  public interface Ordered {
    /**
     * Attests that the expected values must not just be present but must be present in the order
     * they were given.
     */
    void inOrder();
  }

  private abstract static class GeneralSpliterator<E extends @Nullable Object> {
    final Spliterator<E> spliterator;

  @MapFeature.Require(absent = SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testPutIfAbsent_unsupportedPresentExistingValue() {
    try {
      assertEquals(
          "putIfAbsent(present, existingValue) should return present or throw",
          v0(),
          putIfAbsent(e0()));
    } catch (UnsupportedOperationException tolerated) {
    }
    expectUnchanged();
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)

    /**
     * Return the index of any list element that compares as equal to the key. No guarantees are
     * made as to which index is returned, if more than one element compares as equal to the key.
     */
    ANY_PRESENT {
      @Override
      <E extends @Nullable Object> int resultIndex(
          Comparator<? super E> comparator,
          @ParametricNullness E key,
          List<? extends E> list,
          int foundIndex) {

  @CheckForNull
  public V get(K key) {
    int index =
        SortedLists.binarySearch(
            ranges,
            Range::lowerBound,
            Cut.belowValue(key),
            KeyPresentBehavior.ANY_PRESENT,
            KeyAbsentBehavior.NEXT_LOWER);
    if (index == -1) {
      return null;
    } else {
      Range<K> range = ranges.get(index);
      return range.contains(key) ? values.get(index) : null;
    }