attributes {
                        attribute(flavor, 'vanilla')
                    }
                }
            }

            class CategorySelectionRule implements AttributeDisambiguationRule<String> {
                void execute(MultipleCandidatesDetails<String> details) {
                    if (details.candidateValues.contains('chocolate')) {
                        details.closestMatch('chocolate')

package org.gradle.api.internal.attributes

import org.gradle.api.Named
import org.gradle.api.attributes.Attribute
import org.gradle.api.attributes.AttributeCompatibilityRule
import org.gradle.api.attributes.AttributeDisambiguationRule
import org.gradle.api.attributes.CompatibilityCheckDetails
import org.gradle.api.attributes.MultipleCandidatesDetails
import org.gradle.util.AttributeTestUtil
import org.gradle.util.SnapshotTestUtil

import org.gradle.api.artifacts.Configuration;
import org.gradle.api.artifacts.component.ProjectComponentIdentifier;
import org.gradle.api.artifacts.dsl.DependencyHandler;
import org.gradle.api.attributes.AttributeDisambiguationRule;
import org.gradle.api.attributes.AttributeMatchingStrategy;
import org.gradle.api.attributes.Category;
import org.gradle.api.attributes.MultipleCandidatesDetails;
import org.gradle.api.attributes.Usage;

        if (details.consumerValue == "debug" && details.producerValue == "profile") {
            details.compatible()
        }
    }
}
class FlavorSelectionRule implements AttributeDisambiguationRule<String> {
    void execute(MultipleCandidatesDetails<String> details) {
        if (details.candidateValues.contains('tasty')) {
            details.closestMatch('tasty')
        }
    }
}

import org.gradle.api.artifacts.type.ArtifactTypeDefinition;
import org.gradle.api.attributes.Attribute;
import org.gradle.api.attributes.AttributeContainer;
import org.gradle.api.attributes.AttributeDisambiguationRule;
import org.gradle.api.attributes.MultipleCandidatesDetails;
import org.gradle.api.attributes.Usage;
import org.gradle.api.component.ComponentWithVariants;
import org.gradle.api.component.PublishableComponent;

    }

    def "applies disambiguation rules to select variants"() {
        buildFile << """
class OneRule implements AttributeDisambiguationRule<String> {
    void execute(MultipleCandidatesDetails<String> details) {
        details.closestMatch('one')
    }
}
class TwoRule implements AttributeDisambiguationRule<String> {
    void execute(MultipleCandidatesDetails<String> details) {
        details.closestMatch('two')
    }
}

        settingsFile << """
include 'a', 'b'
"""
        buildFile << """
class SelectFreeRule implements AttributeDisambiguationRule<String> {
    void execute(MultipleCandidatesDetails<String> details) {
        details.closestMatch('free')
    }
}
class SelectPaidRule implements AttributeDisambiguationRule<String> {
    void execute(MultipleCandidatesDetails<String> details) {
        details.closestMatch('paid')
    }

                        details.compatible()
                    }
                }
            }

            class DisRule implements AttributeDisambiguationRule<Thing> {
                void execute(MultipleCandidatesDetails<Thing> details) {
                    for (Thing t: details.candidateValues) {
                        if (t.name == 'blue') {

This is done by implementing an link:{javadocPath}/org/gradle/api/attributes/AttributeDisambiguationRule.html[attribute disambiguation rule].

                }
            }

            // Provides a default value of `preferred` if a given attribute is not requested.
            abstract class DefaultingDisambiguationRule implements AttributeDisambiguationRule<String>, org.gradle.api.internal.ReusableAction {
                @Inject
                protected abstract ObjectFactory getObjectFactory()
                @Override