code: func CreateService(t *testing.T, d *daemon.Daemon, opts ...ServiceSpecOpt) string {
  	t.Helper()
  
  	client := d.NewClientT(t)
  	defer client.Close()
  
  	spec := CreateServiceSpec(t, opts...)
  	resp, err := client.ServiceCreate(context.Background(), spec, types.ServiceCreateOptions{})
  	assert.NilError(t, err, "error creating service")
  	return resp.ID
  }
docs: // CreateService creates a service on the passed in swarm daemon.