output: #fixed code
                                @Override
    public void onPageLoad() {
      pageLoaded = true;
      reset();
    }
input: #vulnerable code 
                                @Override
    public void onPageLoad() {
      System.err.println("new page loaded");
      pageLoaded = true;
      reset();
      try {
        Thread.sleep(5000);
        System.out.println(
            "on page load:" + session.getWebInspector().getProtocol().sendCommand(DOM.getDocument())
                .optJSONObject("root").optString("documentURL"));
      } catch (Exception e) {
        e.printStackTrace();
      }
    } 
                              #location 9 
                              #vulnerability type NULL_DEREFERENCE