code: func hOptions(w http.ResponseWriter, r *http.Request) {
  	w.Header().Set("Access-Control-Allow-Origin", "*")
  	w.Header().Set("Access-Control-Allow-Headers", "Content-Type,Access-Control-Allow-Origin")
  	w.WriteHeader(http.StatusOK)
  }
docs: // hOptions sets appropriate response headers in cases like browser-based
  // communication with Abot.