tokens: When the TransactionScope is created , it checks to see if there is a Transaction for the thread ; if one exists then it uses that , otherwise , it creates a new one and pushes it onto the stack .
ner_tags: O O B-Class O O O O O O O O O O O B-Class 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_Structure O