code: func NewRollingUpdater(namespace string, client client.Interface) *RollingUpdater {
  	updater := &RollingUpdater{
  		c:  client,
  		ns: namespace,
  	}
  	// Inject real implementations.
  	updater.scaleAndWait = updater.scaleAndWaitWithScaler
  	updater.getOrCreateTargetController = updater.getOrCreateTargetControllerWithClient
  	updater.waitForReadyPods = updater.pollForReadyPods
  	updater.cleanup = updater.cleanupWithClients
  	return updater
  }
docs: // NewRollingUpdater creates a RollingUpdater from a client.