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));

          if (prev != null) {
            assertSame(prev, current.getPreviousInWriteQueue());
            assertSame(prev.getNextInWriteQueue(), current);
            assertThat(prev.getWriteTime()).isAtMost(current.getWriteTime());
          }
          Object key = current.getKey();
          if (key != null) {
            assertSame(current, segment.getEntry(key, current.getHash()));
          }

    assertSame(mutex, ((SynchronizedNavigableSet<String>) descendingKeySet).mutex);
  }

  public void testDescendingMap() {
    NavigableMap<String, Integer> map = create();
    NavigableMap<String, Integer> descendingMap = map.descendingMap();
    assertTrue(descendingMap instanceof SynchronizedNavigableMap);

    assertFalse(Strings.isNullOrEmpty("a"));
  }

  public void testPadStart_noPadding() {
    assertSame("", Strings.padStart("", 0, '-'));
    assertSame("x", Strings.padStart("x", 0, '-'));
    assertSame("x", Strings.padStart("x", 1, '-'));
    assertSame("xx", Strings.padStart("xx", 0, '-'));
    assertSame("xx", Strings.padStart("xx", 2, '-'));
  }

  public void testPadStart_somePadding() {

  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());
  }

    sortedTable.put("", 42, 'x');
    assertSame(Ordering.natural(), sortedTable.columnComparator());
    assertSame(
        Ordering.natural(),
        ((SortedMap<Integer, Character>) sortedTable.rowMap().values().iterator().next())
            .comparator());

    sortedTable = TreeBasedTable.create(Collections.reverseOrder(), Ordering.usingToString());
    sortedTable.put("", 42, 'x');

    assertSame(mutex, ((SynchronizedNavigableSet<String>) descendingKeySet).mutex);
  }

  public void testDescendingMap() {
    NavigableMap<String, Integer> map = create();
    NavigableMap<String, Integer> descendingMap = map.descendingMap();
    assertTrue(descendingMap instanceof SynchronizedNavigableMap);

    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));