Can prefetch_related be used as a function or should it be used as a method for query optimization?

In Django, prefetch_related is a method of QuerySet used to optimize database queries by loading related objects with a single additional query. It should be used as a method, not as a function. For example:

# Correct
queryset = Book.objects.prefetch_related('authors')

# Incorrect
queryset = prefetch_related(Book.objects, 'authors')  # This call will cause an error

Thus, prefetch_related is called on a QuerySet and returns a new QuerySet with optimization.