code: def add_service(self, service):
          
          if (self.service is None):
              self.service = service
          elif (isinstance(self.service, dict)):
              self.service = [self.service, service]
          else:
              self.service.append(service)
docs: Add a service description.
  
          Handles transition from self.service=None, self.service=dict for a
          single service, and then self.service=[dict,dict,...] for multiple