assertThat(table.row('b').keySet()).containsExactly(1, 2).inOrder();
    assertThat(ImmutableTable.copyOf(table).row('b').keySet()).containsExactly(2, 1).inOrder();
  }

  public void testCopyOfSparse() {
    Table<Character, Integer, String> table = TreeBasedTable.create();
    table.put('x', 2, "foo");
    table.put('r', 1, "bar");
    table.put('c', 3, "baz");
    table.put('b', 7, "cat");