lib/spreadsheet/worksheet.rb
def replace_row idx, *cells
      if(row = @rows[idx]) && cells.size < row.size
        cells.concat Array.new(row.size - cells.size)
      end
      update_row idx, *cells
    end
def replace_row idx, *cells
      if(row = @rows[idx]) && cells.size < row.size
        cells.concat Array.new(row.size - cells.size)
      end
      update_row idx, *cells
    end
Replace the Row at _idx_ with the following arguments. Like #update_row,
 but truncates the Row if there are fewer arguments than Cells in the Row.