64     lru_map_.clear();  in Clear()
79     auto map_iterator = lru_map_.find(key);  in Find()
80     if (map_iterator == lru_map_.end()) {  in Find()
137     if (lru_map_.size() == capacity_) {  in Put()
138       lru_map_.erase(node_list_.back().first);  in Put()
144     lru_map_.emplace(key, node_list_.begin());  in Put()
156     auto map_iterator = lru_map_.find(key);  in Remove()
157     if (map_iterator == lru_map_.end()) {  in Remove()
165     lru_map_.erase(map_iterator);  in Remove()
177     return lru_map_.size();  in Size()
183   std::unordered_map<K, typename std::list<Node>::iterator> lru_map_;  variable