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

  public void testRowKeySetSubSet() {
    sortedTable = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c', "dog", 2, 'd');
    Set<String> set = sortedTable.rowKeySet().subSet("cat", "egg");
    assertEquals(singleton("dog"), set);
    set.clear();