public void sync(Child child) throws IOException, JSONException {
   child.setSynced(true);
   fluentRequest
       .path(String.format("/children/%s", child.getUniqueId()))
       .context(context)
       .param("child", child.toString());
   if (child.opt("current_photo_key") != null
       && !child.optString("current_photo_key").equals("")) {
     fluentRequest.param("current_photo_key", child.optString("current_photo_key"));
   }
   fluentRequest.put();
   repository.update(child);
 }