code: def add_taxes(self, taxes):
          
          # fixme: how to resolve duplicate tax names
          _idx = len(self.taxes)  # current index to prevent overwriting
          for idx, tax in enumerate(taxes):
              tax_key = "tax_" + str(idx + _idx)
              self.taxes[tax_key] = {"name": tax[0], "amount": tax[1]}
docs: Appends the data to the 'taxes' key in the request object
  
          'taxes' should be in format: [("tax_name", "tax_amount")]
          For example:
          [("Other TAX", 700), ("VAT", 5000)]