Method OnMapKey

library/cpp/json/ut/json_reader_fast_ut.cpp:141–144

            }

            bool OnMapKey(const TStringBuf& v) override {
                Events.push_back(TEvent(v, E_KEY));
                return true;
            }

            void OnError(size_t, TStringBuf token) override {
                Events.push_back(TEvent(token, E_ERROR));