.inOrder();
    assertThat(table.row('c').keySet()).containsExactly(0, 3).inOrder();
    assertThat(table.column(5).keySet()).containsExactly('e', 'x').inOrder();
  }

  public void testBuilder_orderRowsAndColumnsBy_dense() {
    ImmutableTable.Builder<Character, Integer, String> builder = ImmutableTable.builder();
    builder.orderRowsBy(Ordering.natural());
    builder.orderColumnsBy(Ordering.natural());