}
  }

  static <R, C, V> RegularImmutableTable<R, C, V> forCells(
      List<Cell<R, C, V>> cells,
      @Nullable Comparator<? super R> rowComparator,
      @Nullable Comparator<? super C> columnComparator) {
    checkNotNull(cells);
    if (rowComparator != null || columnComparator != null) {
      /*
       * This sorting logic leads to a cellSet() ordering that may not be expected and that isn't