How fast is AMP really?(timkadlec.com)

    animation:-amp-start 8s steps(1,end) 0s 1 normal both}
    @keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}

   curl -X POST -H "Content-Type: application/json"  -d "{urls: ['$1'] }" 
   https://content-acceleratedmobilepageurl.googleapis.com
   /v1/ampUrls:batchGet?key=YOUR_AMP_API_KEY

       public static String GET(String url){
        String result = "";
        String ampString = "https://content-acceleratedmobilepageurl.googleapis.com/v1/ampUrls:batchGet?key=YOUR_AMP_API_KEY";
        HttpURLConnection conn = null;
        try {
            URL ampurl = new URL(ampString);
            conn = (HttpURLConnection) ampurl.openConnection();
            conn.setReadTimeout(10000);
            conn.setConnectTimeout(15000);
            conn.setRequestProperty("Content-Type", "application/json");
            conn.setRequestMethod("POST");
            conn.setDoInput(true);
            conn.setDoOutput(true);

            JSONObject jsonObject = new JSONObject();
            jsonObject.accumulate("urls", url);

            OutputStream os = conn.getOutputStream();
            os.write(jsonObject.toString().getBytes("UTF-8"));
            os.close();

            InputStream istream = null;
            istream = conn.getInputStream();
            InputStream in = new BufferedInputStream(istream);
            if(in != null){
                result = convertInputStreamToString(in);
            }
        }
        catch (Exception e) {
            Log.d("News exception", result);
        }finally {
            // Close Stream TODO
            // and disconnect HTTPS connection.
            if (conn != null) {
                conn.disconnect();
            }
        }

    private static String convertInputStreamToString(InputStream inputStream) throws IOException {
        BufferedReader bufferedReader = new BufferedReader( new InputStreamReader(inputStream));
        String line = "";
        String result = "";
        String id = "";
        String ampUrls = "";

        while((line = bufferedReader.readLine()) != null){
            result += line;
        }
        inputStream.close();
        try {
            JSONObject jsonObj = new JSONObject(result);
            // check if jsonObj has ampUrls string - how to do it?

                if (!jsonObj.isNull("ampUrls")){
                    JSONArray contacts = jsonObj.getJSONArray("ampUrls");
                        for (int i = 0; i < contacts.length(); i++) {
                            JSONObject c = contacts.getJSONObject(i);
                            id = c.getString("cdnAmpUrl");
                            }
                    }

            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        return id;

    } //end of convertInputStreamToString