code: func IsSaturated(deployment *apps.Deployment, rs *apps.ReplicaSet) bool {
  	if rs == nil {
  		return false
  	}
  	desiredString := rs.Annotations[DesiredReplicasAnnotation]
  	desired, err := strconv.Atoi(desiredString)
  	if err != nil {
  		return false
  	}
  	return *(rs.Spec.Replicas) == *(deployment.Spec.Replicas) &&
  		int32(desired) == *(deployment.Spec.Replicas) &&
  		rs.Status.AvailableReplicas == *(deployment.Spec.Replicas)
  }
docs: // IsSaturated checks if the new replica set is saturated by comparing its size with its deployment size.
  // Both the deployment and the replica set have to believe this replica set can own all of the desired
  // replicas in the deployment and the annotation helps in achieving that. All pods of the ReplicaSet
  // need to be available.