}

    @Nonnull
    @Override
    public SessionData getData() {
        org.eclipse.aether.SessionData data = session.getData();
        return new SessionData() {
            @Override
            public <T> void set(@Nonnull Key<T> key, @Nullable T value) {
                data.set(key, value);
            }

            @Override

        return eventSpyDispatcher;
    }

    @Override
    public Map<String, Object> getData() {
        if (data == null) {
            data = new HashMap<>();
        }

        return data;
    }

EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING

import java.util.function.Consumer;

import org.apache.maven.api.model.Model;
import org.apache.maven.api.services.ModelBuilderRequest;
import org.apache.maven.api.services.ModelProblemCollector;

/**
 * Holds data relevant for a model building event.
 *
 */
public interface ModelBuildingEvent {

    /**
     * Gets the model being built. The precise state of this model depends on the event being fired.
     *

            // TODO: watch out for module path
        });

        // Note: here, type decides is artifact added to "build path" (for example during resolution)
        // and "build path" is intermediate data that is used to create actual Java classpath/modulepath
        // but to create those, proper filtering should happen via Type properties.
    }

    @Override

import org.codehaus.plexus.classworlds.realm.NoSuchRealmException;
import org.codehaus.plexus.personality.plexus.lifecycle.phase.Disposable;

/**
 * Default extension realm cache implementation. Assumes cached data does not change.
 */
@Named
@Singleton
public class DefaultExtensionRealmCache implements ExtensionRealmCache, Disposable {
    /**
     * CacheKey
     */
    protected static class CacheKey implements Key {

    /**
     * Sets whether the build should be resumed from the data in the resume.properties file.
     * @param resume Whether or not to resume a previous build.
     * @return This request, never {@code null}.
     */
    MavenExecutionRequest setResume(boolean resume);

    /**
     * @return Whether the build should be resumed from the data in the resume.properties file.
     */
    boolean isResume();

          <name>snapshot</name>
          <version>1.0.0+</version>
          <association>
            <type>Snapshot</type>
          </association>
          <description>The current snapshot data in use for this version ("groupId/artifactId/version" only)</description>
        </field>
        <field>
          <name>snapshotVersions</name>
          <version>1.1.0+</version>

        final CollectStepData data = mock(CollectStepData.class);

        RequestTrace haveItFirst = RequestTrace.newChild(null, data)
                .newChild("foo")
                .newChild("bar")
                .newChild("baz");
        assertThat(ReverseTreeRepositoryListener.lookupCollectStepData(haveItFirst), sameInstance(data));

        RequestTrace haveItLast = RequestTrace.newChild(null, "foo")

 * identity of a model. The tag allows for further classification of the associated data on the sole discretion of the
 * model builder.
 *
 */
public interface ModelCache {

    <T> T computeIfAbsent(String groupId, String artifactId, String version, String tag, Supplier<T> data);

    <T> T computeIfAbsent(Source path, String tag, Supplier<T> data);