code: def demo(printer, **kwargs):
      
      for demo_choice in kwargs.keys():
          command = getattr(
              printer,
              demo_choice
              .replace('barcodes_a', 'barcode')
              .replace('barcodes_b', 'barcode')
          )
          for params in DEMO_FUNCTIONS[demo_choice]:
              command(**params)
          printer.cut()
docs: Prints specificed demos. Called when CLI is passed `demo`. This function
      uses the DEMO_FUNCTIONS dictionary.
  
      :param printer: A printer from escpos.printer
      :param kwargs: A dict with a key for each function you want to test. It's
          in this format since it usually comes from argparse.