setup:
        project.eclipse.project.natures = ['nature.for.root']
        child1.eclipse.project.natures = ['nature.for.child1']
        child2.eclipse.project.natures = ['nature.for.child2']
        def modelBuilder = createEclipseModelBuilder()

        when:
        def eclipseModel = modelBuilder.buildAll("org.gradle.tooling.model.eclipse.EclipseProject", project)

        then:

eclipse {
  project {
    file {
      beforeMerged {
        assert it.natures.contains('some.nature.one')
        it.natures << 'some.nature.two'
      }
      whenMerged {
        assert it.natures.contains('some.nature.one')
        assert it.natures.contains('some.nature.two')

        it.natures << 'some.nature.three'
      }
    }
  }
}
        """
        when:

 *     referencedProjects = ['someProject'] as Set
 *
 *     //if you want to append some extra natures in a declarative fashion:
 *     natures 'some.extra.eclipse.nature', 'some.another.interesting.nature'
 *     //if you want to assign natures in a groovy fashion:
 *     natures = ['some.extra.eclipse.nature', 'some.another.interesting.nature']
 *
 *     //if you want to append some extra build command:

        }
    }

    private void addNaturesToXml() {
        Node naturesNode = getXml().appendNode("natures");
        for (String nature : natures) {
            naturesNode.appendNode("nature", nature);
        }
    }

    private void addBuildSpecToXml() {
        Node buildSpec = getXml().appendNode("buildSpec");

                    artifact.getGroupId(), artifact.getArtifactId(), MAVEN_METADATA_XML, Metadata.Nature.RELEASE);
        } else if (LATEST.equals(version)) {
            metadata = new DefaultMetadata(
                    artifact.getGroupId(),
                    artifact.getArtifactId(),
                    MAVEN_METADATA_XML,
                    Metadata.Nature.RELEASE_OR_SNAPSHOT);
        } else if (version.endsWith(SNAPSHOT)) {

                    artifact.getGroupId(), artifact.getArtifactId(), MAVEN_METADATA_XML, Metadata.Nature.RELEASE);
        } else if (LATEST.equals(version)) {
            metadata = new DefaultMetadata(
                    artifact.getGroupId(),
                    artifact.getArtifactId(),
                    MAVEN_METADATA_XML,
                    Metadata.Nature.RELEASE_OR_SNAPSHOT);
        } else if (version.endsWith(SNAPSHOT)) {

        for (String pluginGroup : request.getPluginGroups()) {
            org.eclipse.aether.metadata.Metadata metadata =
                    new DefaultMetadata(pluginGroup, "maven-metadata.xml", DefaultMetadata.Nature.RELEASE_OR_SNAPSHOT);

            requests.add(new MetadataRequest(metadata, null, REPOSITORY_CONTEXT).setTrace(trace));

            for (RemoteRepository repository : request.getRepositories()) {

        Metadata metadata = new DefaultMetadata(
                request.getArtifact().getGroupId(),
                request.getArtifact().getArtifactId(),
                MAVEN_METADATA_XML,
                Metadata.Nature.RELEASE_OR_SNAPSHOT);

        List<MetadataRequest> metadataRequests =
                new ArrayList<>(request.getRepositories().size());

        Metadata metadata = new DefaultMetadata(
                request.getArtifact().getGroupId(),
                request.getArtifact().getArtifactId(),
                MAVEN_METADATA_XML,
                Metadata.Nature.RELEASE_OR_SNAPSHOT);

        List<MetadataRequest> metadataRequests =
                new ArrayList<>(request.getRepositories().size());

   *
   * <p>It is important to note that the primary purpose of the proxy object is to return control to
   * the caller when the timeout elapses; aborting the target method call is of secondary concern.
   * The particular nature and strength of the guarantees made by the proxy is
   * implementation-dependent. However, it is important that each of the methods on the target
   * object behaves appropriately when its thread is interrupted.
   *