code: def onchange_partner_id(self):
          '''
          When you change partner_id it will update the partner_invoice_id,
          partner_shipping_id and pricelist_id of the hotel reservation as well
          ---------------------------------------------------------------------
          @param self: object pointer
          '''
          if not self.partner_id:
              self.partner_invoice_id = False
              self.partner_shipping_id = False
              self.partner_order_id = False
          else:
              addr = self.partner_id.address_get(['delivery', 'invoice',
                                                  'contact'])
              self.partner_invoice_id = addr['invoice']
              self.partner_order_id = addr['contact']
              self.partner_shipping_id = addr['delivery']
              self.pricelist_id = self.partner_id.property_product_pricelist.if onchange_partner_id(self):
          '''
          When you change partner_id it will update the partner_invoice_id,
          partner_shipping_id and pricelist_id of the hotel reservation as well
          ---------------------------------------------------------------------
          @param self: object pointer
          '''
          if not self.partner_id:
              self.partner_invoice_id = False
              self.partner_shipping_id = False
              self.partner_order_id = False
          else:
              addr = self.partner_id.address_get(['delivery', 'invoice',
                                                  'contact'])
              self.partner_invoice_id = addr['invoice']
              self.partner_order_id = addr['contact']
              self.partner_shipping_id = addr['delivery']
              self.pricelist_id = self.partner_id.property_product_pricelist.id
docs: When you change partner_id it will update the partner_invoice_id,
          partner_shipping_id and pricelist_id of the hotel reservation as well
          ---------------------------------------------------------------------
          @param self: object pointer