code: public static Tag method(@Nullable HttpServletRequest request) {
          return request == null ? METHOD_UNKNOWN : Tag.of("method", request.getMethod());
      }
docs: Creates a {@code method} tag based on the {@link HttpServletRequest#getMethod()
  method} of the given {@code request}.
  
  @param request the request
  @return the method tag whose value is a capitalized method (e.g. GET).