/**
     * Returns the set of variants to select from during attribute matching, or an empty list of this
     * component does not support attribute matching.
     */
    List<? extends VariantGraphResolveState> getVariantsForAttributeMatching();

    /**
     * Returns the variant to use when attribute-based variant selection is not enabled.
     */
    @Nullable

        if (!targetComponentState.getCandidatesForGraphVariantSelection().getVariantsForAttributeMatching().isEmpty()) {
            VariantGraphResolveState selected = variantSelector.selectByAttributeMatching(
                consumerAttributes,
                explicitRequestedCapabilities,

        assert !candidates.getVariantsForAttributeMatching().isEmpty();

        ComponentGraphResolveMetadata targetComponent = targetComponentState.getMetadata();
        AttributeMatcher attributeMatcher = consumerSchema.withProducer(targetComponent.getAttributesSchema());

        List<? extends VariantGraphResolveState> allVariants = candidates.getVariantsForAttributeMatching();

        }

        // Use attribute matching if it is supported.
        if (!targetComponentState.getCandidatesForGraphVariantSelection().getVariantsForAttributeMatching().isEmpty()) {
            VariantGraphResolveState selected = variantSelector.selectByAttributeMatching(
                consumerAttributes,
                explicitRequestedCapabilities, targetComponentState,

    private static List<ResolvedVariantResult> computeSelectableVariantResults(DefaultLocalComponentGraphResolveState component) {
        return component.getCandidatesForGraphVariantSelection()
            .getVariantsForAttributeMatching()
            .stream()
            .flatMap(variant -> variant.prepareForArtifactResolution().getArtifactVariants().stream())
            .map(variant -> new DefaultResolvedVariantResult(

        if (!targetComponentState.getCandidatesForGraphVariantSelection().getVariantsForAttributeMatching().isEmpty()) {
            VariantGraphResolveState selected = variantSelector.selectByAttributeMatching(
                consumerAttributes,
                explicitRequestedCapabilities,

            this.variants = component.allVariantsForGraphResolution.get();
            this.component = component;
        }

        @Override
        public List<? extends VariantGraphResolveState> getVariantsForAttributeMatching() {
            return variants;
        }

        @Nullable
        @Override

            .collect(Collectors.toList());
    }

    public List<AssessedCandidate> assessGraphSelectionCandidates(GraphSelectionCandidates candidates) {
        return candidates.getVariantsForAttributeMatching().stream()
            .map(VariantGraphResolveState::getMetadata)
            .map(variantMetadata -> assessCandidate(variantMetadata.getName(), variantMetadata.getCapabilities(), variantMetadata.getAttributes()))

    class TestGraphCandidates implements GraphSelectionCandidates {
        List<VariantGraphResolveState> variants = []

        @Override
        List<? extends VariantGraphResolveState> getVariantsForAttributeMatching() {
            variants.findAll { it -> !it.attributes.isEmpty()}
        }

        @Override