@Experimental
@Immutable
public interface Dependency extends Artifact {

    /**
     * The dependency type.
     *
     * @return the dependency type, never {@code null}
     */
    @Nonnull
    Type getType();

    @Nonnull
    DependencyScope getScope();

    boolean isOptional();

    /**
     * Creates a {@code DependencyCoordinate} based on this {@code Dependency}.
     *

    </repository>
  </repositories>

  <dependencies>
    <dependency>
      <!-- groupId deliberately missing -->
      <artifactId>b</artifactId>
      <version>0.1</version>
    </dependency>
    <dependency>
      <groupId>org.apache.maven.its</groupId>
      <artifactId>a</artifactId>
      <version>0.1</version>
    </dependency>
  </dependencies>

Jason van Zyl <******@****.***> 1243627215 +0000

  <groupId>test</groupId>
  <artifactId>versionless-managed-dependency.xml</artifactId>
  <version>0.0.1-SNAPSHOT</version>

  <dependencies>
    <dependency>
      <groupId>org.apache.maven.its</groupId>
      <artifactId>a</artifactId>
    </dependency>
  </dependencies>

  <dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>org.apache.maven.its</groupId>

            for (Dependency dependency : project.getDependencies()) {
                if (dependency.getGroupId() == null
                        || dependency.getGroupId().isEmpty()
                        || dependency.getArtifactId() == null
                        || dependency.getArtifactId().isEmpty()
                        || dependency.getVersion() == null

    @Override
    public List<org.eclipse.aether.graph.Dependency> toDependencies(
            Collection<DependencyCoordinate> dependencies, boolean managed) {
        return dependencies == null ? null : map(dependencies, d -> toDependency(d, managed));
    }

    @Override
    public abstract org.eclipse.aether.graph.Dependency toDependency(DependencyCoordinate dependency, boolean managed);

    @Override

                    Object key = getDependencyKey().apply(managedDependency);
                    Dependency dependency = dependencies.get(key);
                    if (dependency != null) {
                        Dependency merged = mergeDependency(dependency, managedDependency, false, context);
                        if (merged != dependency) {

public class DefaultDependency implements Dependency {

    private final InternalSession session;
    private final org.eclipse.aether.graph.Dependency dependency;
    private final String key;

    public DefaultDependency(
            @Nonnull InternalSession session, @Nonnull org.eclipse.aether.graph.Dependency dependency) {
        this.session = nonNull(session, "session");
        this.dependency = nonNull(dependency, "dependency");

    private final org.eclipse.aether.graph.Dependency dependency;

    public DefaultDependencyCoordinate(
            @Nonnull InternalSession session, @Nonnull org.eclipse.aether.graph.Dependency dependency) {
        this.session = nonNull(session, "session");
        this.dependency = nonNull(dependency, "dependency");
    }

    @Nonnull
    public org.eclipse.aether.graph.Dependency getDependency() {
        return dependency;

                        String.format(
                                "The requested dependency version range '%s' does not specify an upper bound",
                                dependency.getVersion()),
                        dependency.getGroupId(),
                        dependency.getArtifactId(),
                        dependency.getVersion());
            }