tokens: There are many ways to get round this , but the quickest ( albeit dirtiest ) would be to store the message in a static variable somewhere so the 404 handler can access it once the process gets there , e.g .
ner_tags: O O O O O O O O O O O O O O O O O O O O O O O O B-Data_Type O O O O B-Error_Name O O O O O O O O O O O O