tokens: All these instances get pointers to PopulationMember and ownsMembers_ is always set true - this looks quite a bit fishy and you might want to debug with breakpoints in your destructors/constructors to find out the lifecycle of each population and its members .
ner_tags: O O O O B-Data_Type O B-Class O B-Variable O O O B-Value O 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-Class O O O O