docs: public static HttpServletResponse getHttpServletResponse(Object response)
      {
          // unwrap the response until we find a HttpServletResponse
          while (response != null)
          {
              if (response instanceof HttpServletResponse)
              {
                  // found
                  return (HttpServletResponse) response;
              }
              if (response instanceof ServletResponseWrapper)
              {
                  // unwrap
                  response = ((ServletResponseWrapper) response).getResponse();
              }
              // no more possibilities to find a HttpServletResponse
              break;
          }
          return null; // not found
      }