code: func (gce *Cloud) UpdateURLMap(urlMap *compute.UrlMap) (*compute.UrlMap, error) {
  	op, err := gce.service.UrlMaps.Update(gce.projectID, urlMap.Name, urlMap).Do()
  	if err != nil {
  		return nil, err
  	}
  	if err = gce.waitForGlobalOp(op); err != nil {
  		return nil, err
  	}
  	return gce.service.UrlMaps.Get(gce.projectID, urlMap.Name).Do()
  }
docs: // UpdateURLMap applies the given UrlMap as an update, and returns the new UrlMap.