Call the invalidate_caches() method on all path entry finders
        stored in sys.path_importer_caches (where implemented).

def invalidate_caches(cls):
        """Call the invalidate_caches() method on all path entry finders
        stored in sys.path_importer_caches (where implemented)."""
        for finder in sys.path_importer_cache.values():
            if hasattr(finder, 'invalidate_caches'):
                finder.invalidate_caches()