Unload asset library

If I don’t call registerLibrary, I cannot call unloadLibrary, right?
I tried loading from file and from the manifest again without calling registerLibrary afterwards and just waiting for a few minutes to see RAM changes, but looks like there is no difference.

Edit: Not calling registerLibrary, but calling loadedLibrary.unload doesn’t have effect either.

Edit 2: I’m curious about unloadLibrary code:

if (library != null)
{
	cache.clear(name + ":");//HTML5 libraries don't seem to have cache, so this will be a loose run
	library.onChange.remove(library_onChange);
	library.unload();//this function is a placeholder
}

I might be missing something, but I couldn’t find what marks loaded assets for GC.