}
        if (cachedFilteredDependencyStates == null) {
            cachedFilteredDependencyStates = cacheFilteredDependencyStates(spec, cachedDependencyStates);
        }
        return cachedFilteredDependencyStates;
    }

    private List<DependencyState> cacheFilteredDependencyStates(ExcludeSpec spec, List<DependencyState> from) {
        if (from.isEmpty()) {
            return from;
        }