public void testEmpty_comparator() {
    SortedSet<String> set = of();
    assertSame(Ordering.natural(), set.comparator());
  }

  public void testEmpty_headSet() {
    SortedSet<String> set = of();
    assertSame(set, set.headSet("c"));
  }

  public void testEmpty_tailSet() {
    SortedSet<String> set = of();
    assertSame(set, set.tailSet("f"));
  }

  public void testEmpty_subSet() {

    try {
      try {
        throw exception;
      } catch (Throwable e) {
        throw closer.rethrow(e);
      } finally {
        closer.close();
      }
    } catch (Throwable expected) {
      assertSame(exception, expected);
    }

    assertTrue(c1.isClosed());
    assertTrue(c2.isClosed());

    assertTrue(suppressor.suppressions.isEmpty());
  }

    assertTrue(descendingSet instanceof SynchronizedNavigableSet);
    assertSame(MUTEX, ((SynchronizedNavigableSet<String>) descendingSet).mutex);
  }

  public void testHeadSet_E() {
    NavigableSet<String> map = create();
    SortedSet<String> headSet = map.headSet("a");
    assertTrue(headSet instanceof SynchronizedSortedSet);
    assertSame(MUTEX, ((SynchronizedSortedSet<String>) headSet).mutex);
  }

        assertThrows(UncheckedExecutionException.class, () -> cache.getUnchecked(new Object()));
    assertThat(expected).hasCauseThat().isEqualTo(cause);

    Object newValue = new Object();
    valueRef.set(newValue);
    assertSame(newValue, cache.getUnchecked(new Object()));
  }

  public void testGetUnchecked_unchecked() {
    final RuntimeException cause = new RuntimeException();
    final AtomicReference<Object> valueRef = new AtomicReference<>();

    assertSame(
        "toArray(sameSizeE[]) should return the given array", array, collection.toArray(array));
    expectArrayContentsAnyOrder(createSamplesArray(), array);
  }

  @CollectionFeature.Require(KNOWN_ORDER)
  public void testToArray_rightSizedArray_ordered() {
    E[] array = getSubjectGenerator().createArray(getNumElements());
    assertSame(

    assertSame(
        "toArray(sameSizeE[]) should return the given array", array, collection.toArray(array));
    expectArrayContentsAnyOrder(createSamplesArray(), array);
  }

  @CollectionFeature.Require(KNOWN_ORDER)
  public void testToArray_rightSizedArray_ordered() {
    E[] array = getSubjectGenerator().createArray(getNumElements());
    assertSame(

    assertNotSame(mod, unmod);
    assertSame(unmod, Multimaps.unmodifiableListMultimap(unmod));
    ImmutableListMultimap<String, Integer> immutable =
        ImmutableListMultimap.of("a", 1, "b", 2, "a", 3);
    assertSame(immutable, Multimaps.unmodifiableListMultimap(immutable));
    assertSame(
        immutable, Multimaps.unmodifiableListMultimap((ListMultimap<String, Integer>) immutable));

    try {
      try {
        throw exception;
      } catch (Throwable e) {
        throw closer.rethrow(e);
      } finally {
        closer.close();
      }
    } catch (Throwable expected) {
      assertSame(exception, expected);
    }

    assertTrue(c1.isClosed());
    assertTrue(c2.isClosed());

    assertTrue(suppressor.suppressions.isEmpty());
  }

    assertSame(copy, ImmutableSortedMap.copyOf(copy));
    assertSame(Ordering.natural(), copy.comparator());
  }

  public void testCopyOfSingletonMap() {
    ImmutableSortedMap<String, Integer> copy =
        ImmutableSortedMap.copyOf(Collections.singletonMap("one", 1));
    assertMapEquals(copy, "one", 1);
    assertSame(copy, ImmutableSortedMap.copyOf(copy));

    assertEquals(Collections.<String, Integer>emptyMap(), copy);
    assertSame(copy, ImmutableBiMap.copyOf(copy));
    assertSame(ImmutableBiMap.of(), copy);
  }

  public void testCopyOfSingletonMap() {
    ImmutableBiMap<String, Integer> copy =
        ImmutableBiMap.copyOf(Collections.singletonMap("one", 1));
    assertMapEquals(copy, "one", 1);
    assertSame(copy, ImmutableBiMap.copyOf(copy));
  }