virtual int GetUsersList(std::vector<std::string> * usersList) const = 0;
virtual int AddUser(const std::string & login) const = 0;
virtual int DelUser(const std::string & login) const = 0;
virtual int GetUsersList(std::vector<std::string> * usersList) const = 0;
virtual int AddUser(const std::string & login) const = 0;
virtual int DelUser(const std::string & login) const = 0;