Currently, mojo configuration is done externally to the container, in the
  DefaultPluginManager in the maven-core API. In order to get from here to
  there, we need to do several things to add capability to the default
  configuration of plexus. This document will detail those changes.

Container Enhancements

* ExpressionEvaluator

  Currently, the expression evaluator used to resolve configuration values

     *
     * @param pluginDescriptor The plugin descriptor in which to save the class realm and the plugin artifacts, must not
     *            be {@code null}.
     * @param session The build session from which to pick the current project and repository settings, must not be
     *            {@code null}.
     * @param parent The parent class realm for the plugin, may be {@code null} to use the Maven core realm.

    void addEdge(Vertex from, Vertex to) throws CycleDetectedException {
        from.children.add(to);
        to.parents.add(from);
        List<String> cycle = findCycle(to);
        if (cycle != null) {
            // remove edge which introduced cycle
            removeEdge(from, to);
            throw new CycleDetectedException(

        // do nothing
    }

    /**
     * Invoked after all projects were built.
     *
     * This callback is intended to allow extensions to perform cleanup of any
     * allocated external resources after the build. It is invoked on best-effort
     * basis and may be missed due to an Error or RuntimeException in Maven core
     * code.
     *
     * @param session the Maven session

     * parameters that would be required to delegate to a stateless component. Saving the session (in a thread-local
     * variable) is our best effort to record any state that is required to enable proper delegation.
     *
     * @param session The currently active session, may be {@code null}.
     */
    void setSession(MavenSession session);

    /**
     * Gets the currently active session.

 * <p>
 * Should only be implemented by DebugResolutionListener.  Remove this
 * when the ResolutionListener interface deprecation of the manageArtifact
 * method (and the [yet to be done] addition of these methods to that
 * interface) has had a chance to propagate to all interested plugins.
 */
@Deprecated
public interface ResolutionListenerForDepMgmt {
    void manageArtifactVersion(Artifact artifact, Artifact replacement);

     * either on the class-path or on the module-path. The project needs to make a choice
     * (possibly using heuristic rules), then to add the dependency in only one of the options
     * identified by {@link PathType}.</p>
     *
     * @return file paths to place on the different tool options
     */
    @Nonnull
    Map<PathType, List<Path>> getDispatchedPaths();

    @Nonnull

     * parent and child completely decoupled by injecting deep copies of objects into the child rather than the original
     * objects from the parent.
     *
     * @param child The child model into which to merge the values inherited from the parent, must not be
     *            <code>null</code>.
     * @param parent The (read-only) parent model from which to inherit the values, may be <code>null</code>.

     * from the information that is available at the point the problem occurs and as such merely serves as a best effort
     * to provide information to the user to track the problem back to its origin.
     *
     * @return The identifier of the model from which the problem originated or an empty string if unknown, never
     *         {@code null}.
     */
    String getModelId();

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