@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}.
     *

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

    @Nonnull
    private DependencyCoordinate toDependency(org.apache.maven.api.model.Dependency dependency) {
        return new DependencyCoordinate() {
            @Override
            public String getGroupId() {
                return dependency.getGroupId();
            }

            @Override
            public String getArtifactId() {
                return dependency.getArtifactId();
            }

    org.eclipse.aether.repository.LocalRepository toRepository(LocalRepository repository);

    List<org.eclipse.aether.graph.Dependency> toDependencies(
            Collection<DependencyCoordinate> dependencies, boolean managed);

    org.eclipse.aether.graph.Dependency toDependency(DependencyCoordinate dependency, boolean managed);

    List<org.eclipse.aether.artifact.Artifact> toArtifacts(Collection<Artifact> artifacts);

        final Dependency dependency = new Dependency();
        dependency.setGroupId("org.apache");
        dependency.setArtifactId("apache");
        dependency.setVersion("1");

        assertNotNull(this.newModelResolver().resolveModel(dependency.getDelegate(), new AtomicReference<>()));
        assertEquals("1", dependency.getVersion());
    }

    @Test

                && !dependency.getSystemPath().isEmpty();

        Map<String, String> props = null;
        if (system) {
            props = Collections.singletonMap(MavenArtifactProperties.LOCAL_PATH, dependency.getSystemPath());
        }

        Artifact artifact = new DefaultArtifact(
                dependency.getGroupId(),
                dependency.getArtifactId(),

    @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) {

                Dependency dependency = new Dependency();

                dependency.setArtifactId(a.getArtifactId());
                dependency.setGroupId(a.getGroupId());
                dependency.setVersion(a.getVersion());
                dependency.setScope(a.getScope());
                dependency.setType(a.getType());
                dependency.setClassifier(a.getClassifier());

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");