When multiple versions of the same class have been loaded (e.g. PluginUpdateChecker 1.2
and 1.3), this factory will always use the latest available version. Register class
versions by calling {@link PucFactory::addVersion()}.
At the moment it can only build instances of the PluginUpdateChecker class. Other classes
are intended mainly for internal use and refer directly to specific implementations. If you
want to instantiate one of them anyway, you can use {@link PucFactory::getLatestClassVersion()}
to get the class name and then create it with
new $class(...)
.