return nothing;
        }
        if (excludes.size() == 1) {
            return forExclude(excludes.iterator().next());
        }
        Set<ExcludeSpec> result = new HashSet<>();
        for (ExcludeMetadata exclude : excludes) {
            result.add(forExclude(exclude));
        }
        return factory.anyOf(result);
    }

    public ExcludeSpec nothing() {
        return nothing;