/// <summary> <!-- {{{1 --> Get cells from column index
/// </summary>
/// <param name="idx"></param>
/// <returns></returns>
public IEnumerable <Cell> CellsFromCol(SudokuHouseIndex idx)
{
idx.AssertWhenInvalid();
return(idx.ToCellsIndexInCol().Select(x => this.board.ElementAt(x.ToInt())));
}
