extern std::multimap<std::string, std::string> read_key_value (std::istream& s);
extern int get_required_int (std::multimap<std::string, std::string> const & kv, std::string k);
extern float get_required_float (std::multimap<std::string, std::string> const & kv, std::string k);
extern std::multimap<std::string, std::string> read_key_value (std::istream& s);
extern int get_required_int (std::multimap<std::string, std::string> const & kv, std::string k);
extern float get_required_float (std::multimap<std::string, std::string> const & kv, std::string k);