pkg/mock/mockserver/mockserver.go
func (ms *MockServers) StartAt(idx int) (err error) {
	ms.mu.Lock()
	defer ms.mu.Unlock()

	if ms.Servers[idx].ln == nil {
		ms.Servers[idx].ln, err = net.Listen(ms.Servers[idx].Network, ms.Servers[idx].Address)
		if err != nil {
			return fmt.Errorf("failed to listen %v", err)
		}
	}

	svr := grpc.NewServer()
	pb.RegisterKVServer(svr, &mockKVServer{})
	ms.Servers[idx].GrpcServer = svr

	ms.wg.Add(1)
	go func(svr *grpc.Server, l net.Listener) {
		svr.Serve(l)
	}(ms.Servers[idx].GrpcServer, ms.Servers[idx].ln)
	return nil
}
func (ms *MockServers) StartAt(idx int) (err error) {
	ms.mu.Lock()
	defer ms.mu.Unlock()

	if ms.Servers[idx].ln == nil {
		ms.Servers[idx].ln, err = net.Listen(ms.Servers[idx].Network, ms.Servers[idx].Address)
		if err != nil {
			return fmt.Errorf("failed to listen %v", err)
		}
	}

	svr := grpc.NewServer()
	pb.RegisterKVServer(svr, &mockKVServer{})
	ms.Servers[idx].GrpcServer = svr

	ms.wg.Add(1)
	go func(svr *grpc.Server, l net.Listener) {
		svr.Serve(l)
	}(ms.Servers[idx].GrpcServer, ms.Servers[idx].ln)
	return nil
}
// StartAt restarts mock server at given index.