+ std::unordered_map<std::string, tag_t>::iterator val;
+ //for(auto val : *(this->tag_ids))
+ //(*this->tag_names)[val.second] = val.first;
+ for(val = this->tag_ids->begin(); val != this->tag_ids->end(); ++val)
+ (*this->tag_names)[val->second] = val->first;
+