code: def add_member(self, service_name, servicegroup_name):
          
          servicegroup = self.find_by_name(servicegroup_name)
          if not servicegroup:
              servicegroup = Servicegroup({'servicegroup_name': servicegroup_name,
                                           'alias': servicegroup_name,
                                           'members': service_name})
              self.add(servicegroup)
          else:
              servicegroup.add_members(service_name)
docs: Add a member (service) to this servicegroup
  
          :param service_name: member (service) name
          :type service_name: str
          :param servicegroup_name: servicegroup name
          :type servicegroup_name: str
          :return: None