def barcode(opts = {})
      data = format_for_subset_c_if_applicable send(barcodable)
      if (subset = opts[:subset])
        case subset
        when 'A'; Barby::Code128A.new data
        when 'B'; Barby::Code128B.new data
        when 'C'; Barby::Code128C.new data
        end
      else
        most_efficient_barcode_for data
      end
    end
def barcode(opts = {})
      data = format_for_subset_c_if_applicable send(barcodable)
      if (subset = opts[:subset])
        case subset
        when 'A'; Barby::Code128A.new data
        when 'B'; Barby::Code128B.new data
        when 'C'; Barby::Code128C.new data
        end
      else
        most_efficient_barcode_for data
      end
    end
Returns a Code128 barcode instance.

 opts:
 :subset - specify the Code128 subset to use ('A', 'B', or 'C').