/// Which of the required packages are installed?
static void getAvailable();
/// Is the (required) package available?
static bool isAvailable(std::string const & name);
/// Has the package been required?
bool isRequired(std::string const & name) const;
/// Which of the required packages are installed?
static void getAvailable();
/// Is the (required) package available?
static bool isAvailable(std::string const & name);
/// Has the package been required?
bool isRequired(std::string const & name) const;