old_contents: # -*- coding: utf-8 -*-
  
  from odoo import api, fields, models
  
  
  class ResConfigSettings(models.TransientModel):
      _inherit = 'res.config.settings'
  
      sale_tax_id = fields.Many2one('account.tax', string="Default Sale Tax", related='company_id.account_sale_tax_id')
      iface_tax_included = fields.Selection([('subtotal', 'Tax-Excluded Price'), ('total', 'Tax-Included Price')], related="company_id.iface_tax_included", required=True)
      module_pos_mercury = fields.Boolean(string="Integrated Card Payments", help="The transactions are processed by Vantiv. Set your Vantiv credentials on the related payment journal.")
      pos_sales_price = fields.Boolean("Multiple Product Prices", config_parameter='point_of_sale.pos_sales_price')
      pos_pricelist_setting = fields.Selection([
          ('percentage', 'Multiple prices per product (e.g. customer segments, currencies)'),
          ('formula', 'Price computed from formulas (discounts, margins, roundings)')
          ], string="POS Pricelists", config_parameter='point_of_sale.pos_pricelist_setting')
  
      @api.onchange('pos_sales_price')
      def _onchange_sale_price(self):
          if not self.pos_sales_price:
              self.pos_pricelist_setting = False
          if self.pos_sales_price and not self.pos_pricelist_setting:
              self.pos_pricelist_setting = 'percentage'
  
      @api.onchange('pos_pricelist_setting')
      def _onchange_pos_pricelist_setting(self):
          if self.pos_pricelist_setting == 'percentage':
              self.update({
                  'group_product_pricelist': True,
                  'group_sale_pricelist': True,
                  'group_pricelist_item': False,
              })
          elif self.pos_pricelist_setting == 'formula':
              self.update({
                  'group_product_pricelist': False,
                  'group_sale_pricelist': True,
                  'group_pricelist_item': True,
              })
          else:
              self.update({
                  'group_product_pricelist': False,
                  'group_sale_pricelist': False,
                  'group_pricelist_item': False,
              })
  
new_contents: # -*- coding: utf-8 -*-
  
  from odoo import api, fields, models
  
  
  class ResConfigSettings(models.TransientModel):
      _inherit = 'res.config.settings'
  
      sale_tax_id = fields.Many2one('account.tax', string="Default Sale Tax", related='company_id.account_sale_tax_id')
      iface_tax_included = fields.Selection([('subtotal', 'Tax-Excluded Price'), ('total', 'Tax-Included Price')], related="company_id.iface_tax_included", required=True)
      module_pos_mercury = fields.Boolean(string="Integrated Card Payments", help="The transactions are processed by Vantiv. Set your Vantiv credentials on the related payment journal.")
      pos_sales_price = fields.Boolean("Multiple Product Prices", config_parameter='point_of_sale.pos_sales_price')
      pos_pricelist_setting = fields.Selection([
          ('percentage', 'Multiple prices per product (e.g. customer segments, currencies)'),
          ('formula', 'Price computed from formulas (discounts, margins, roundings)')
          ], string="POS Pricelists", config_parameter='point_of_sale.pos_pricelist_setting')
  
      @api.onchange('pos_sales_price')
      def _onchange_pos_sales_price(self):
          if not self.pos_sales_price:
              self.pos_pricelist_setting = False
          if self.pos_sales_price and not self.pos_pricelist_setting:
              self.pos_pricelist_setting = 'percentage'
  
      @api.onchange('pos_pricelist_setting')
      def _onchange_pos_pricelist_setting(self):
          if self.pos_pricelist_setting == 'percentage':
              self.update({
                  'group_product_pricelist': True,
                  'group_sale_pricelist': True,
                  'group_pricelist_item': False,
              })
          elif self.pos_pricelist_setting == 'formula':
              self.update({
                  'group_product_pricelist': False,
                  'group_sale_pricelist': True,
                  'group_pricelist_item': True,
              })
          else:
              self.update({
                  'group_product_pricelist': False,
                  'group_sale_pricelist': False,
                  'group_pricelist_item': False,
              })
  
subject: update method name to avoid conflict with another method