private List<DependencyState> dependencies(ExcludeSpec spec) {
        List<? extends DependencyMetadata> dependencies = dependencies();
        if (cachedDependencyStates == null) {
            cachedDependencyStates = cacheDependencyStates(dependencies);
        }
        if (cachedFilteredDependencyStates == null) {
            cachedFilteredDependencyStates = cacheFilteredDependencyStates(spec, cachedDependencyStates);
        }