I am working on a PocketMine-MP plugin with an API accessible by other plugins on the server. Other plugins can't use the class, so I return it (via ::class) from a method on an object that the other plugin can access. Other plugins need to extend this class.
So that gets to my problem. I can't find a way to extend from a class that's only known at runtime.
$var = Provider::class;
class ConfigProvider extends $var {}
/* $var will come from a function call otherwise this would be pointless */