code: func parseACRLoginServerFromImage(image string) string {
  	match := acrRE.FindAllString(image, -1)
  	if len(match) == 1 {
  		return match[0]
  	}
  	return ""
  }
docs: // parseACRLoginServerFromImage takes image as parameter and returns login server of it.
  // Parameter `image` is expected in following format: foo.azurecr.io/bar/imageName:version
  // If the provided image is not an acr image, this function will return an empty string.