tokens: I will have three elements in my vector : ( 1 , 2) , ( 1 , 2) again , and ( 5 , 6 ) .
ner_tags: O O O O O O O O O B-Value I-Value I-Value I-Value O B-Value I-Value I-Value I-Value O O O B-Value I-Value I-Value I-Value I-Value O