* specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.internal.impl;

import java.util.*;

import org.apache.maven.project.CycleDetectedException;

class Graph {
    private enum DfsState {
        VISITING,
        VISITED
    }

    final Map<String, Vertex> vertices = new LinkedHashMap<>();

    public Vertex getVertex(String id) {
        return vertices.get(id);

import java.util.List;
import java.util.Map;
import java.util.Set;

class Graph {

    final Map<String, Set<String>> graph = new LinkedHashMap<>();

    synchronized void addEdge(String from, String to) throws CycleDetectedException {
        if (graph.computeIfAbsent(from, l -> new HashSet<>()).add(to)) {
            List<String> cycle = visitCycle(graph, Collections.singleton(to), new HashMap<>(), new LinkedList<>());

         *       v3-v4
         *
         */
        v1 = graph.addVertex(new ArtifactMetadata("g", "a1", "1.0"));
        graph.setEntry(v1);
        v2 = graph.addVertex(new ArtifactMetadata("g", "a2", "1.0"));
        v3 = graph.addVertex(new ArtifactMetadata("g", "a3", "1.0"));
        v4 = graph.addVertex(new ArtifactMetadata("g", "a4", "1.0"));

        // v1-->v2
        graph.addEdge(v1, v2, new MetadataGraphEdge("1.1", true, null, null, 2, 1));

         *   v1<
         *      v3-v4
         *
         */
        graph = new MetadataGraph(4, 3);
        v1 = graph.addVertex(new ArtifactMetadata("g", "a1", "1.0"));
        graph.setEntry(v1);
        v2 = graph.addVertex(new ArtifactMetadata("g", "a2", "1.0"));
        v3 = graph.addVertex(new ArtifactMetadata("g", "a3", "1.0"));
        v4 = graph.addVertex(new ArtifactMetadata("g", "a4", "1.0"));

        // v1-->v2

    Node getNode(org.eclipse.aether.graph.DependencyNode node);

    Node getNode(org.eclipse.aether.graph.DependencyNode node, boolean verbose);

    @Nonnull
    Artifact getArtifact(@Nonnull org.eclipse.aether.artifact.Artifact artifact);

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

                            request.isOptional(),
                            map(request.getExclusions(), this::toExclusion)));
        }
    }

    private org.eclipse.aether.graph.Exclusion toExclusion(Exclusion exclusion) {
        return new org.eclipse.aether.graph.Exclusion(exclusion.getGroupId(), exclusion.getArtifactId(), "*", "*");
    }

    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;

import org.eclipse.aether.util.graph.manager.ClassicDependencyManager;
import org.eclipse.aether.util.graph.selector.AndDependencySelector;
import org.eclipse.aether.util.graph.selector.ExclusionDependencySelector;
import org.eclipse.aether.util.graph.transformer.ChainedDependencyGraphTransformer;
import org.eclipse.aether.util.graph.transformer.ConflictResolver;
import org.eclipse.aether.util.graph.transformer.NearestVersionSelector;

import org.eclipse.aether.util.graph.manager.ClassicDependencyManager;
import org.eclipse.aether.util.graph.selector.AndDependencySelector;
import org.eclipse.aether.util.graph.selector.ExclusionDependencySelector;
import org.eclipse.aether.util.graph.transformer.ChainedDependencyGraphTransformer;
import org.eclipse.aether.util.graph.transformer.ConfigurableVersionSelector;

         * Construct a new value source, using the supplied object as the root from
         * which to start, and using expressions split at the dot ('.') to navigate
         * the object graph beneath this root.
         * @param root the root of the graph.
         */
        public ObjectBasedValueSource(Object root) {
            super(true);
            this.root = root;
        }

        /**