@Override
    Iterator<Cell<C, R, V>> cellIterator() {
      return Iterators.transform(original.cellSet().iterator(), Tables::transposeCell);
    }
  }

  private static <
          R extends @Nullable Object, C extends @Nullable Object, V extends @Nullable Object>
      Cell<C, R, V> transposeCell(Cell<R, C, V> cell) {
    return immutableCell(cell.getColumnKey(), cell.getRowKey(), cell.getValue());
  }

  /**