void addClient(const std::string &appid, unsigned layer,
unsigned surface, const std::string &role);
void addClient(const std::string &appid, unsigned layer, const std::string &role);
void addClient(const std::string &appid, unsigned layer,
unsigned surface, const std::string &role);
void addClient(const std::string &appid, unsigned layer, const std::string &role);