Set<String> expected = Collections.singleton("a");
    assertEquals(expected, Optional.of("a").asSet());
  }

  public void testAsSet_absent() {
    assertTrue("Returned set should be empty", Optional.absent().asSet().isEmpty());
  }

  public void testAsSet_presentIsImmutable() {
    Set<String> presentAsSet = Optional.of("a").asSet();
    try {
      presentAsSet.add("b");
      fail();

      }
    }.test();
  }

  /**
   * Returns {@link Method} instances for the tests that assume multisets support duplicates so that
   * the test of {@code Multisets.forSet()} can suppress them.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static List<Method> getIteratorDuplicateInitializingMethods() {
    return Arrays.asList(

    expectContents(contents);
  }

  /**
   * Returns {@link Method} instances for the remove tests that assume multisets support duplicates
   * so that the test of {@code Multisets.forSet()} can suppress them.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static List<Method> getRemoveDuplicateInitializingMethods() {
    return Arrays.asList(

    ImmutableSortedSet<Integer> asSet = RANGE_SET_ONE.asSet(DiscreteDomain.integers());
    assertEquals(expectedSet, asSet);
    assertThat(asSet).containsExactlyElementsIn(expectedSet).inOrder();
    assertTrue(asSet.containsAll(expectedSet));
    SerializableTester.reserializeAndAssert(asSet);
  }

  public void testAsSetHeadSet() {

   *
   * <p><b>Note:</b> {@code a.asSet(d).equals(b.asSet(d))} does not imply {@code a.equals(b)}! For
   * example, {@code a} and {@code b} could be {@code [2..4]} and {@code (1..5)}, or the empty
   * ranges {@code [3..3)} and {@code [4..4)}.
   *
   * <p><b>Warning:</b> Be extremely careful what you do with the {@code asSet} view of a large

   *
   * <p><b>Note:</b> {@code a.asSet(d).equals(b.asSet(d))} does not imply {@code a.equals(b)}! For
   * example, {@code a} and {@code b} could be {@code [2..4]} and {@code (1..5)}, or the empty
   * ranges {@code [3..3)} and {@code [4..4)}.
   *
   * <p><b>Warning:</b> Be extremely careful what you do with the {@code asSet} view of a large

    Set<String> expected = Collections.singleton("a");
    assertEquals(expected, Optional.of("a").asSet());
  }

  public void testAsSet_absent() {
    assertTrue("Returned set should be empty", Optional.absent().asSet().isEmpty());
  }

  public void testAsSet_presentIsImmutable() {
    Set<String> presentAsSet = Optional.of("a").asSet();
    try {
      presentAsSet.add("b");
      fail();

    expectContents(contents);
  }

  /**
   * Returns {@link Method} instances for the remove tests that assume multisets support duplicates
   * so that the test of {@code Multisets.forSet()} can suppress them.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static List<Method> getRemoveDuplicateInitializingMethods() {
    return Arrays.asList(

  }

  public void testToSet() {
    assertThat(fluent(1, 2, 3, 4).toSet()).containsExactly(1, 2, 3, 4).inOrder();
  }

  public void testToSet_removeDuplicates() {
    assertThat(fluent(1, 2, 1, 2).toSet()).containsExactly(1, 2).inOrder();
  }

  public void testToSet_empty() {
    assertTrue(fluent().toSet().isEmpty());
  }

  public void testToSortedSet() {

   *
   * <p><b>Comparison to {@code java.util.Optional}:</b> this method has no equivalent in Java 8's
   * {@code Optional} class. However, this common usage:
   *
   * <pre>{@code
   * for (Foo foo : possibleFoo.asSet()) {
   *   doSomethingWith(foo);
   * }
   * }</pre>
   *
   * ... can be replaced with:
   *
   * <pre>{@code
   * possibleFoo.ifPresent(foo -> doSomethingWith(foo));
   * }</pre>
   *