46   virtual bool Insert(const Key& key, const Value& val) = 0;
48   virtual bool Lookup(const Key& key, Value* val) = 0;
192   bool Insert(const size_t& key, const string& val) override {  in Insert()  argument
194     map_.insert(make_pair(key, val));  in Insert()
208   bool Lookup(const size_t& key, string* val) override {  in Lookup()  argument
212       *val = it->second;  in Lookup()
228   bool Insert(const size_t& key, const string& val) override {  in Insert()  argument
229     Node n(key, val);  in Insert()
238   bool Lookup(const size_t& key, string* val) override {  in Lookup()  argument
244       *val = n.val_;  in Lookup()
251     explicit Node(const size_t key, const string& val) : key_(key), val_(val) {}  in Node()