return rx - lx;
            } else {
                return lx - rx;
            }
        };

        Map<String, Lifecycle> lifecyclesMap = lookupLifecycles();

        // ensure canonical order of standard lifecycles
        return lifecyclesMap.values().stream()
                .peek(l -> Objects.requireNonNull(l.getId(), "A lifecycle must have an id."))

public class DefaultProjectDependencyGraph implements ProjectDependencyGraph {

    private final ProjectSorter sorter;

    private final List<MavenProject> allProjects;

    private final Map<MavenProject, Integer> order;

    private final Map<String, MavenProject> projects;

    /**
     * Creates a new project dependency graph based on the specified projects.
     *

import org.eclipse.aether.resolution.ArtifactDescriptorResult;

/**
 * Maven relocation source.
 * Note: implementations of this component should avoid the "default" name (has special meaning in Eclipse Sisu) and
 * explicitly order implementations using Sisu priorities.
 *
 * @since 4.0.0
 */
public interface MavenArtifactRelocationSource {
    /**
     * Returns {@link Artifact} instance where to relocate to, or {@code null}.
     *

     *
     * @return the severity level of this problem, never {@code null}
     */
    @Nonnull
    Severity getSeverity();

    /**
     * The different severity levels for a problem, in decreasing order.
     *
     * @since 4.0.0
     */
    @Experimental
    enum Severity {
        FATAL, //
        ERROR, //
        WARNING //
    }

         * NOTE: This is primarily to keep backward-compat with Maven 2.x which did not validate that dependencies are
         * unique within a single POM. Upon multiple declarations, 2.x just kept the last one but retained the order of
         * the first occurrence. So when we're in lenient/compat mode, we have to deal with such broken POMs and mimic

// TODO lifecycles being executed
// TODO what runs in each phase
// TODO plugins that need downloading
// TODO project dependencies that need downloading
// TODO unfortunately the plugins need to be downloaded in order to get the plugin.xml file. need to externalize this
//      from the plugin archive.
// TODO this will be the class that people get in IDEs to modify

/**
 * MavenExecutionPlan
 */

     */
    @Override
    String id();

    /**
     * Collection of phases for this lifecycle
     */
    Collection<Phase> phases();

    /**
     * Pre-ordered list of phases.
     * If not provided, a default order will be computed.
     */
    default Optional<List<String>> orderedPhases() {
        return Optional.empty();
    }

    /**
     * A phase in the lifecycle.
     */

 * that exhibits the problem.
 *
 */
public interface Problem {

    /**
     * The different severity levels for a problem, in decreasing order.
     */
    enum Severity {
        FATAL, //
        ERROR, //
        WARNING //
    }

    /**

 * @see org.apache.maven.api.services.DependencyResolver
 */
@Experimental
@Immutable
public enum DependencyScope {

    /**
     * None. Allows you to declare dependencies (for example to alter reactor build order) but in reality dependencies
     * in this scope are not part of any path scope.
     */
    NONE("none", false),

    /**

     */
    @Nonnull
    ChecksumAlgorithm select(@Nonnull String algorithmName);

    /**
     * Returns a collection of {@link ChecksumAlgorithm} in same order as algorithm names are ordered, or throws if
     * any of the algorithm name is not supported. The returned collection has equal count of elements as passed in