*
 * @since 1.0-milestone-5
 */
public interface HierarchicalElement extends Element {

    /**
     * Returns the parent of this element, or {@code null} if there is no parent.
     *
     * @return The parent of this element, or {@code null} if there is no parent.
     * @since 1.0-milestone-5
     */
    @Nullable
    HierarchicalElement getParent();

    /**

        visit(rootProject, controller, projects);
        return projects;
    }

    void visit(HierarchicalElement element, BuildController buildController, Map<String, CustomModel> results) {
        results.put(element.getName(), buildController.getModel(element, CustomModel.class));
        for (HierarchicalElement child : element.getChildren()) {
            visit(child, buildController, results);
        }
    }

import org.gradle.tooling.model.HasGradleProject;
import org.gradle.tooling.model.HierarchicalElement;
import org.gradle.tooling.model.UnsupportedMethodException;

import java.io.File;

/**
 * Represents the basic information about an Eclipse project.
 *
 * @since 1.0-milestone-3
 */
public interface HierarchicalEclipseProject extends HierarchicalElement, HasGradleProject {

    /**
     * {@inheritDoc}
     */
    @Override

import org.gradle.tooling.model.DomainObjectSet;
import org.gradle.tooling.model.HierarchicalElement;
import org.gradle.tooling.model.UnsupportedMethodException;

/**
 * Represents the information about the IDEA project.
 *
 * @since 1.0-milestone-5
 */
public interface IdeaProject extends HierarchicalElement {

    /**
     * Returns the Java language settings for this project.
     *

import org.gradle.tooling.model.HasGradleProject;
import org.gradle.tooling.model.HierarchicalElement;
import org.gradle.tooling.model.UnsupportedMethodException;

import javax.annotation.Nullable;

/**
 * Represents information about the IDEA module.
 *
 * @since 1.0-milestone-5
 */
public interface IdeaModule extends HierarchicalElement, HasGradleProject {

    /**

import javax.annotation.Nullable;
import java.io.File;

/**
 * Represents a Gradle project.
 *
 * @since 1.0-milestone-5
 */
public interface GradleProject extends HierarchicalElement, BuildableElement, ProjectModel {
    /**
     * Returns the identifier for this Gradle project.
     *
     * @since 2.13
     */
    @Override
    ProjectIdentifier getProjectIdentifier();

    /**