virtual std::string kdm_as_xml () const = 0;
virtual void kdm_as_xml (boost::filesystem::path out) const = 0;
virtual std::string kdm_id () const = 0;
virtual std::string kdm_as_xml () const = 0;
virtual void kdm_as_xml (boost::filesystem::path out) const = 0;
virtual std::string kdm_id () const = 0;