@Override
 public CurrentTopic get() throws Exception {
   try {
     String json = client.getStringContent(topicRequestUrl(serverUrl));
     return parseResponseJson(json);
   } catch (NoContentException ex) {
     return CurrentTopic.empty();
   }
 }
 private CurrentTopic parseResponseJson(String json) {
   try {
     JSONObject obj = new JSONObject(json);
     String id = obj.getString("id");
     String text = obj.getString("text");
     return CurrentTopic.create(id, text);
   } catch (JSONException e) {
     throw new RuntimeException(e);
   }
 }