std::vector<Format const *> const
getReachableTo(std::string const & target, bool clear_visited);
///
std::vector<Format const *> const
getReachable(std::string const & from, bool only_viewable,
bool clear_visited,
std::vector<Format const *> const
getReachableTo(std::string const & target, bool clear_visited);
///
std::vector<Format const *> const
getReachable(std::string const & from, bool only_viewable,
bool clear_visited,