docs: private void readErrorAttributes() {
  
          WrappedSession session = getSession().getSession();
          m_requestedPage = (String)session.getAttribute(PATH);
          m_throwable = (Throwable)session.getAttribute(THROWABLE);
  
          // remove the attributes after read to keep the session clean
          session.removeAttribute(THROWABLE);
          session.removeAttribute(PATH);
      }