code: func (b BaseDeploymentGenerator) structuredGenerate() (
  	podSpec v1.PodSpec,
  	labels map[string]string,
  	selector metav1.LabelSelector,
  	err error,
  ) {
  	err = b.validate()
  	if err != nil {
  		return
  	}
  	podSpec = buildPodSpec(b.Images)
  	labels = map[string]string{}
  	labels["app"] = b.Name
  	selector = metav1.LabelSelector{MatchLabels: labels}
  	return
  }
docs: // structuredGenerate: determine the fields of a deployment. The struct that
  // embeds BaseDeploymentGenerator should assemble these pieces into a
  // runtime.Object.