code: func (o *SetImageOptions) Validate() error {
  	errors := []error{}
  	if o.All && len(o.Selector) > 0 {
  		errors = append(errors, fmt.Errorf("cannot set --all and --selector at the same time"))
  	}
  	if len(o.Resources) < 1 && cmdutil.IsFilenameSliceEmpty(o.Filenames, o.Kustomize) {
  		errors = append(errors, fmt.Errorf("one or more resources must be specified as <resource> <name> or <resource>/<name>"))
  	}
  	if len(o.ContainerImages) < 1 {
  		errors = append(errors, fmt.Errorf("at least one image update is required"))
  	} else if len(o.ContainerImages) > 1 && hasWildcardKey(o.ContainerImages) {
  		errors = append(errors, fmt.Errorf("all containers are already specified by *, but saw more than one container_name=container_image pairs"))
  	}
  	return utilerrors.NewAggregate(errors)
  }
docs: // Validate makes sure provided values in SetImageOptions are valid