code: func (n *NetworkServerAPI) GetRandomDevAddr(ctx context.Context, req *empty.Empty) (*ns.GetRandomDevAddrResponse, error) {
  	devAddr, err := storage.GetRandomDevAddr(storage.RedisPool(), config.C.NetworkServer.NetID)
  	if err != nil {
  		return nil, errToRPCError(err)
  	}
  
  	return &ns.GetRandomDevAddrResponse{
  		DevAddr: devAddr[:],
  	}, nil
  }
docs: // GetRandomDevAddr returns a random DevAddr.