need it so that empty directory does not get deleted...

     * Sets the project's class realm. <strong>Warning:</strong> This is an internal utility method that is only public
     * for technical reasons, it is not part of the public API. In particular, this method can be changed or deleted
     * without prior notice and must not be used by plugins.
     *
     * @param classRealm The class realm hosting the build extensions of this project, may be {@code null}.
     */

 * under the License.
 */
package org.apache.maven.lifecycle.internal;

/**
 * A task that is a goal.
 * <p>
 * <strong>NOTE:</strong> This class is not part of any public api and can be changed or deleted without prior notice.
 *
 * @since 3.0
 */
public final class GoalTask extends Task {
    public GoalTask(String pluginGoal) {
        super(pluginGoal);
    }

 * internal utility component that is only public for technical reasons, it is not part of the public API. In
 * particular, this component can be changed or deleted without prior notice.
 *
 * @since 3.0
 */
@Named
@Singleton
public class DefaultLegacySupport implements LegacySupport {

/**
 * Assists the project builder. <strong>Warning:</strong> This is an internal utility class that is only public for
 * technical reasons, it is not part of the public API. In particular, this class can be changed or deleted without
 * prior notice.
 *
 * @since 3.0
 */
public class EnvironmentUtils {

    private static Properties envVars;

    /**

/**
 * Caches project class realms. <strong>Warning:</strong> This is an internal utility interface that is only public for
 * technical reasons, it is not part of the public API. In particular, this interface can be changed or deleted without
 * prior notice.
 *
 */
public interface ProjectRealmCache {

    /**
     * A cache key.
     */
    interface Key {
        // marker interface for cache keys
    }

    /**

 * Assists in firing execution events. <strong>Warning:</strong> This is an internal utility interface that is only
 * public for technical reasons, it is not part of the public API. In particular, this interface can be changed or
 * deleted without prior notice.
 *
 */
public interface ExecutionEventCatapult {

    void fire(ExecutionEvent.Type eventType, MavenSession session, MojoExecution mojoExecution);

import org.apache.maven.plugin.MojoExecution;
import org.apache.maven.project.MavenProject;

/**
 * <strong>NOTE:</strong> This class is not part of any public api and can be changed or deleted without prior notice.
 * @since 3.0
 */
public class PhaseRecorder {
    private String lastLifecyclePhase;

    private final MavenProject project;

    public PhaseRecorder(MavenProject project) {

import org.apache.maven.plugin.version.PluginVersionResolutionException;

/**
 * <p>
 * Calculates the task segments in the build
 * </p>
 * <strong>NOTE:</strong> This class is not part of any public api and can be changed or deleted without prior notice.
 *
 * @since 3.0
 */
public interface LifecycleTaskSegmentCalculator {
    List<TaskSegment> calculateTaskSegments(MavenSession session)

/**
 * <p>
 * Wraps individual MojoExecutions, containing information about completion status and scheduling.
 * </p>
 * <strong>NOTE:</strong> This class is not part of any public api and can be changed or deleted without prior notice.
 *
 * @since 3.0
 */
public class ExecutionPlanItem {
    private final MojoExecution mojoExecution;

    public ExecutionPlanItem(MojoExecution mojoExecution) {