* It shouldn't be too slow, or the whole chain will pay the price.
 */
public class NormalizingExcludeFactory extends DelegatingExcludeFactory {
    private final Intersections intersections;
    private final Unions unions;

    public NormalizingExcludeFactory(ExcludeFactory delegate) {
        super(delegate);
        this.intersections = new Intersections(this);

    }

    def "intersection of #one with #other = #expected using normalizing factory"() {
        given:
        factory = new NormalizingExcludeFactory(factory)

        expect:
        factory.allOf(one, other) == expected
        factory.allOf(other, one) == expected

        where:

import spock.lang.Shared
import spock.lang.Specification
import spock.lang.Unroll

class NormalizingExcludeFactoryTest extends Specification implements ExcludeTestSupport {

    def setup() {
        factory = new NormalizingExcludeFactory(factory)
    }

    @Shared
    private DefaultIvyArtifactName artifactName = new DefaultIvyArtifactName("a", "b", "c")

    @Unroll("#left ∪ #right = #expected")
    def "union of two elements"() {