code: func CheckRules(files ...string) int {
  	failed := false
  
  	for _, f := range files {
  		if n, errs := checkRules(f); errs != nil {
  			fmt.Fprintln(os.Stderr, "  FAILED:")
  			for _, e := range errs {
  				fmt.Fprintln(os.Stderr, e.Error())
  			}
  			failed = true
  		} else {
  			fmt.Printf("  SUCCESS: %d rules found\n", n)
  		}
  		fmt.Println()
  	}
  	if failed {
  		return 1
  	}
  	return 0
  }
docs: // CheckRules validates rule files.