code: private JSONObject getCriteria(JSONObject payload) throws JSONException {
      if (payload.has("criteria")) {
        JSONObject json = payload.getJSONObject("criteria");
        return json;
      } else if (payload.has("using")) {
        return getCriteriaFromWebDriverSelector(payload);
      } else {
        throw new InvalidSelectorException("wrong format for the findElement command " + payload);
      }
    }
docs: create the criteria for the request. If the request follows the webdriver protocol, maps it to
  a criteria ios-driver understands.