public static HttpRequest httpReq() {
        return new HttpRequest().requestPreparer(reqBuilder -> getCachedAuthorization().map(a -> {
            reqBuilder.addHeader("Authorization", a.getAuthorizationField());
            return reqBuilder;
        }));
    }
Base methods to issue OAuth authenticated HTTP requests against gc.com
main/src/main/java/cgeo/geocaching/connector/gc/GCAuthAPI.java