code: func (scaler *DeploymentScaler) ScaleSimple(namespace, name string, preconditions *ScalePrecondition, newSize uint) error {
  	deployment, err := scaler.c.Deployments(namespace).Get(name)
  	if err != nil {
  		return ScaleError{ScaleGetFailure, "Unknown", err}
  	}
  	if preconditions != nil {
  		if err := preconditions.ValidateDeployment(deployment); err != nil {
  			return err
  		}
  	}
  
  	// TODO(madhusudancs): Fix this when Scale group issues are resolved (see issue #18528).
  	// For now I'm falling back to regular Deployment update operation.
  	deployment.Spec.Replicas = int(newSize)
  	if _, err := scaler.c.Deployments(namespace).Update(deployment); err != nil {
  		if errors.IsInvalid(err) {
  			return ScaleError{ScaleUpdateInvalidFailure, deployment.ResourceVersion, err}
  		}
  		return ScaleError{ScaleUpdateFailure, deployment.ResourceVersion, err}
  	}
  	return nil
  }
docs: // ScaleSimple is responsible for updating a deployment's desired replicas count.