// ----------------------------------------------------------------------

    /**
     * How the test project is set up:
     *
     * 1. dependencyManagement lists dependencies on a & b,
     *    with an exclusion on c in b.
     * 2. the child project lists a dependency on project a only
     * 3. a depends on b (which is transitive to the child project),
     *    and b depends on c.
     *

    </dependency>
    <dependency>
      <groupId>org.eclipse.sisu</groupId>
      <artifactId>org.eclipse.sisu.plexus</artifactId>
      <exclusions>
        <exclusion>
          <groupId>*</groupId>
          <artifactId>*</artifactId>
        </exclusion>
      </exclusions>
    </dependency>
    <dependency>
      <groupId>org.codehaus.plexus</groupId>
      <artifactId>plexus-classworlds</artifactId>
    </dependency>

            for (Exclusion exclusion : d.getExclusions()) {
                if (request.getValidationLevel() < ModelBuildingRequest.VALIDATION_LEVEL_MAVEN_3_0) {
                    validateCoordinateId(
                            prefix,
                            "exclusions.exclusion.groupId",
                            problems,

      <artifactId>maven-resolver-tools</artifactId>
      <version>${resolverVersion}</version>
      <scope>test</scope>
      <exclusions>
        <exclusion>
          <groupId>org.slf4j</groupId>
          <artifactId>slf4j-nop</artifactId>
        </exclusion>
      </exclusions>
    </dependency>
  </dependencies>

  <pluginRepositories>
    <pluginRepository>
      <releases>

    </dependency>
    <dependency>
      <groupId>org.codehaus.plexus</groupId>
      <artifactId>plexus-interactivity-api</artifactId>
      <exclusions>
        <exclusion>
          <groupId>*</groupId>
          <artifactId>*</artifactId>
        </exclusion>
      </exclusions>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-api</artifactId>
    </dependency>

        Dependency dep1 = new Dependency();
        dep1.setGroupId( "test" );
        dep1.setArtifactId( "test-artifact" );
        dep1.setVersion( "1" );
        dep1.setType( "jar" );

        Exclusion exc = new Exclusion();
        exc.setGroupId( "test" );
        exc.setArtifactId( "test-artifact3" );

        dep1.addExclusion( exc );

        Dependency dep2 = new Dependency();
        dep2.setGroupId( "test" );

        }

        if (!d.getExclusions().isEmpty()) {
            List<String> exclusions = new ArrayList<>();

            for (Exclusion exclusion : d.getExclusions()) {
                exclusions.add(exclusion.getGroupId() + ':' + exclusion.getArtifactId());
            }

            artifact.setDependencyFilter(new ExcludesArtifactFilter(exclusions));
        }

        return artifact;
    }

package org.apache.maven.artifact.resolver.filter;

import java.util.List;

import org.apache.maven.artifact.Artifact;

/**
 * Filter to exclude from a list of artifact patterns.
 *
 * TODO I think this is equiv. to exclusion set filter in maven-core
 */
public class ExcludesArtifactFilter extends IncludesArtifactFilter {
    public ExcludesArtifactFilter(List<String> patterns) {
        super(patterns);
    }

        return candidate.withExclusions(Stream.concat(candidate.getExclusions().stream(), exclusions.stream())
                .toList());
    }

    private boolean match(Exclusion exclusion, org.apache.maven.api.model.Dependency candidate) {
        return match(exclusion.getGroupId(), candidate.getGroupId())
                && match(exclusion.getArtifactId(), candidate.getArtifactId());
    }

     * @return the obligation, or {@code null} if unspecified
     */
    @Nullable
    Boolean getOptional();

    /**
     * {@return transitive dependencies to exclude}
     */
    @Nonnull
    Collection<Exclusion> getExclusions();