docs: public static Tag exception(RequestEvent event) {
          Throwable exception = event.getException();
          if (exception == null) {
              return EXCEPTION_NONE;
          }
          ContainerResponse response = event.getContainerResponse();
          if (response != null) {
              int status = response.getStatus();
              if (status == 404 || isRedirection(status)) {
                  return EXCEPTION_NONE;
              }
          }
          if (exception.getCause() != null) {
              exception = exception.getCause();
          }
          String simpleName = exception.getClass().getSimpleName();
          return Tag.of("exception", StringUtils.isNotEmpty(simpleName) ? simpleName
                  : exception.getClass().getName());
      }