}

  public void testColumnKeySet_oneEntry() {
    table = create("a", 1, 'X');
    assertThat(table.columnKeySet().toString()).isEqualTo("[1]");
  }

  public void testRowEntrySetContains() {
    table =
        sortedTable =
            create(
                "a", 2, 'X', "a", 2, 'X', "b", 3, 'X', "b", 2, 'X', "c", 10, 'X', "c", 10, 'X', "c",