code: public static Observable<JSONObject> sendDataInBackground(JSONObject data, AVQuery<? extends AVInstallation> query) {
      AVPush push = new AVPush();
      push.setData(data);
      push.setQuery(query);
      return push.sendInBackground();
    }
docs: A helper method to concisely send a push to a query. This method is equivalent to
  
  <pre>
  AVPush push = new AVPush();
  push.setData(data);
  push.setQuery(query);
  push.sendInBackground(callback);
  </pre>
  
  @param data The entire data of the push message. See the push guide for more details on the
  data format.
  @param query A AVInstallation query which specifies the recipients of a push.