code: def edit_service_group(self, loadbal_id, group_id, allocation=None,
                             port=None, routing_type=None, routing_method=None):
          
  
          mask = 'virtualServers[serviceGroups[services[groupReferences]]]'
  
          load_balancer = self.lb_svc.getObject(id=loadbal_id, mask=mask)
          virtual_servers = load_balancer['virtualServers']
  
          for virtual_server in virtual_servers:
              if virtual_server['id'] == group_id:
                  service_group = virtual_server['serviceGroups'][0]
                  if allocation is not None:
                      virtual_server['allocation'] = allocation
                  if port is not None:
                      virtual_server['port'] = port
                  if routing_type is not None:
                      service_group['routingTypeId'] = routing_type
                  if routing_method is not None:
                      service_group['routingMethodId'] = routing_method
                  break
  
          return self.lb_svc.editObject(load_balancer, id=loadbal_id)
docs: Edit an existing service group.
  
          :param int loadbal_id: The id of the loadbal where the service resides
          :param int group_id: The id of the service group
          :param int allocation: the % of connections to allocate to the group
          :param int port: the port of the service group
          :param int routing_type: the routing type to set on the service group
          :param int routing_method: The routing method to set on the group