code: protected Map<String, Object> getErrorAttributes(ServerRequest request,
  			boolean includeStackTrace) {
  		return this.errorAttributes.getErrorAttributes(request, includeStackTrace);
  	}
docs: Extract the error attributes from the current request, to be used to populate error
  views or JSON payloads.
  @param request the source request
  @param includeStackTrace whether to include the error stacktrace information
  @return the error attributes as a Map.