assertEquals(singleton("dog"), set);
    set.clear();
    assertTrue(set.isEmpty());
    assertEquals(ImmutableSet.of("bar", "foo"), sortedTable.rowKeySet());
  }

  public void testRowMapComparator() {
    sortedTable = TreeBasedTable.create();
    assertSame(Ordering.natural(), sortedTable.rowMap().comparator());

    sortedTable = TreeBasedTable.create(Collections.reverseOrder(), Ordering.usingToString());