static std::string get_store_file_name(std::string device_id, plp::Date *ltime);
static void store(std::string device_id, std::list<std::string> *string_list);
void load();
static std::string get_store_file_name(std::string device_id, plp::Date *ltime);
static void store(std::string device_id, std::list<std::string> *string_list);
void load();