Method OnBeginMap

library/cpp/yson/json/json_writer.cpp:169–174

    }

    void TJsonWriter::OnBeginMap() {
        if (IsWriteAllowed()) {
            EnterNode();
            JsonWriter->OpenMap();
        }
    }

    void TJsonWriter::OnKeyedItem(TStringBuf name) {
        if (IsWriteAllowed()) {