whs, err := GetWebhooksWithRevision(ctx, client, DefaultRevisionName)
	if err != nil {
		return err
	}
	if len(whs) == 0 {
		// no revision with default, no action required.
		return nil
	}
	if len(whs) > 1 {
		return fmt.Errorf("expected a single webhook for default revision")
	}
	webhook := whs[0]
	for i := range webhook.Webhooks {

	}
	if len(revWebhooks) > 1 {
		return "", fmt.Errorf("cannot modify tag: found multiple canonical webhooks with revision %q", opts.Revision)
	}

	whs, err := GetWebhooksWithTag(ctx, client.Kube(), opts.Tag)
	if err != nil {
		return "", err
	}
	if len(whs) > 0 && !opts.Overwrite {
		return "", fmt.Errorf("revision tag %q already exists, and --overwrite is false", opts.Tag)
	}