when:
        run 'copy'

        then:
        file('dest').assertHasDescendants('emptyDir', 'dummy', 'yet/another/veryEmptyDir')
        file('dest/emptyDir').assertIsEmptyDir()
        file('dest/yet/another/veryEmptyDir').assertIsEmptyDir()

        when:
        run 'copy'

        then:
        skipped(':copy')

        when:
        file('files/more').createDir()

        def javaHome = new File(temporaryFolder, "localGradle").tap { mkdirs() }
        def metadata = detector.getMetadata(testLocation(javaHome))

        then:
        metadata
        tmpDir.assertIsEmptyDir()
    }

    def "can detect metadata of #displayName"() {
        given:
        def execHandleFactory = createExecHandleFactory(systemProperties)

        when:

     */
    public TestFile assertContainsDescendants(String... descendants) {
        return assertContainsDescendants(Arrays.asList(descendants));
    }

    public TestFile assertIsEmptyDir() {
        assertHasDescendants();
        return this;
    }

    public Set<String> allDescendants() {
        Set<String> names = new TreeSet<>();
        if (isDirectory()) {