final List<MutableCell<R, C, V>> insertionOrder = new ArrayList<>();
    final Table<R, C, MutableCell<R, C, V>> table = HashBasedTable.create();

    void put(R row, C column, V value, BinaryOperator<V> merger) {
      MutableCell<R, C, V> oldCell = table.get(row, column);
      if (oldCell == null) {
        MutableCell<R, C, V> cell = new MutableCell<>(row, column, value);
        insertionOrder.add(cell);

    ImmutableTable.Builder<Character, Integer, String> builder = new ImmutableTable.Builder<>();

    StringHolder holder = new StringHolder();
    holder.string = "foo";
    Table.Cell<Character, Integer, String> mutableCell =
        new Tables.AbstractCell<Character, Integer, String>() {
          @Override
          public Character getRowKey() {
            return 'K';
          }

          @Override