code: public JSONObject invalidateAccessToken() throws IOException, KiteException, JSONException {
          String url = routes.get("api.token");
          Map<String, Object> params = new HashMap<>();
          params.put("api_key", apiKey);
          params.put("access_token", accessToken);
          return new KiteRequestHandler(proxy).deleteRequest(url, params, apiKey, accessToken);
      }
docs: Kills the session by invalidating the access token.
  @return JSONObject which contains status
  @throws KiteException is thrown for all Kite trade related errors.
  @throws IOException is thrown when there is connection related error.