code: def room_reserve(self):
          
          hotel_res_obj = self.env['hotel.reservation']
          for res in self:
              rec = (hotel_res_obj.create
                     ({'partner_id': res.partner_id.id,
                       'partner_invoice_id': res.partner_invoice_id.id,
                       'partner_order_id': res.partner_order_id.id,
                       'partner_shipping_id': res.partner_shipping_id.id,
                       'checkin': res.check_in,
                       'checkout': res.check_out,
                       'warehouse_id': res.warehouse_id.id,
                       'pricelist_id': res.pricelist_id.id,
                       'adults': res.adults,
                       'reservation_line': [(0, 0,
                                             {'reserve': [(6, 0,
                                                           [res.room_id.id])],
                                              'name': (res.room_id and
                                                       res.room_id.name or '')
                                              })]
                       }))
          return rec
docs: This method create a new record for hotel.reservation
          -----------------------------------------------------
          @param self: The object pointer
          @return: new record set for hotel reservation.