package org.apache.maven.api;

import org.apache.maven.api.annotations.Experimental;
import org.apache.maven.api.annotations.Nullable;

/**
 * A dependency exclusion.
 *
 * @since 4.0.0
 * @see DependencyCoordinates#getExclusions()
 */
@Experimental
public interface Exclusion {
    @Nullable
    String getGroupId();

    @Nullable
    String getArtifactId();

  <dependencies>
    <dependency>
      <groupId>gid</groupId>
      <artifactId>aid</artifactId>
      <version>1.0</version>
      <exclusions>
        <exclusion>
          <groupId></groupId>
        </exclusion>
      </exclusions>
    </dependency>
  </dependencies>

  <dependencies>
    <dependency>
      <groupId>gid</groupId>
      <artifactId>aid</artifactId>
      <version>1.0</version>
      <exclusions>
        <exclusion>
          <groupId>test?</groupId>
          <artifactId>*</artifactId>
        </exclusion>
      </exclusions>
    </dependency>
  </dependencies>

            if (exclusion != null) {
                if (this.exclusions.isEmpty()) {
                    this.exclusions = new ArrayList<>();
                }
                this.exclusions.add(exclusion);
            }
            return this;
        }

        public DependencyCoordinatesFactoryRequest build() {

                dependency.getOptional() != null ? dependency.isOptional() : null,
                exclusions);
    }

    private Exclusion convert(org.apache.maven.model.Exclusion exclusion) {
        return new Exclusion(exclusion.getGroupId(), exclusion.getArtifactId(), "*", "*");
    }

    private void setArtifactProperties(ArtifactDescriptorResult result, Model model) {
        String downloadUrl = null;

import org.apache.maven.model.Exclusion;

/**
 * Filter to exclude from a list of artifact patterns.
 */
public class ExclusionArtifactFilter implements ArtifactFilter {

    private final List<Exclusion> exclusions;
    private final List<Predicate<Artifact>> predicates;

    public ExclusionArtifactFilter(List<Exclusion> exclusions) {
        this.exclusions = exclusions;
        this.predicates =

import static org.junit.jupiter.api.Assertions.assertTrue;

/**
 * Tests {@code Exclusion}.
 *
 */
class ExclusionTest {

    @Test
    void testHashCodeNullSafe() {
        new Exclusion().hashCode();
    }

    @Test
    void testEqualsNullSafe() {
        assertFalse(new Exclusion().equals(null));

        new Exclusion().equals(new Exclusion());
    }

    @Test
    void testEqualsIdentity() {

                && equals(d1.getExclusions(), d2.getExclusions());
    }

    private boolean equals(Collection<Exclusion> ce1, Collection<Exclusion> ce2) {
        if (ce1.size() == ce2.size()) {
            Iterator<Exclusion> i1 = ce1.iterator();
            Iterator<Exclusion> i2 = ce2.iterator();
            while (i1.hasNext() && i2.hasNext()) {
                if (!equals(i1.next(), i2.next())) {

      <artifactId>maven-core-it-support</artifactId>
      <version>1.3</version>
      <scope>runtime</scope>
      <exclusions>
        <exclusion>
          <groupId>commons-lang</groupId>
          <artifactId>commons-lang</artifactId>
        </exclusion>
      </exclusions>
    </dependency>
  </dependencies>

        MavenProject project = session.getCurrentProject();

        Exclusion exclusion = new Exclusion();
        exclusion.setGroupId( "org.apache.maven.its" );
        exclusion.setArtifactId( "a" );

        new ProjectBuilder( project ).addDependency( "org.apache.maven.its", "b", "0.1", Artifact.SCOPE_RUNTIME,
                                                     exclusion );

        Set<Artifact> artifactDependencies =