code: public String getDefaultFor(int status){
          String defaultPage = defaultPages.get(status);
          return (defaultPage != null) ? defaultPage : "<html><body><h2>HTTP Status " + status + "</h2></body></html>";
      }
docs: Returns the default error page for a given status code.
  Guaranteed to never be null.
  @param status
  @return String representation of the default error page.