public static <T extends Collection<?>> T flatten(Object[] elements, T addTo, boolean flattenMaps) {
        return flatten(asList(elements), addTo, flattenMaps);
    }

    public static <T extends Collection<?>> T flatten(Object[] elements, T addTo) {
        return flatten(asList(elements), addTo);
    }

    public static <T extends Collection<?>> T flatten(Collection<?> elements, T addTo) {

        flatten(s4) == [parent.path, "1:dir1", "2:dir2", "2:dir5/and/more", "1:dir6"]

        def s5 = s4.plus(dir1)
        flatten(s5) == [parent.path, "1:dir1", "1:dir6"]

        def s6 = s3.plus(dir1)
        flatten(s6) == [parent.path, "1:dir1", "1:dir6"]

        def s7 = s3.plus(parent)
        flatten(s7) == [parent.path]
    }

    def "has a nice toString representation"() {

        expect:
        def s1 = snapshot(dir1dir2dir3, dir1dir5)
        flatten(s1) == [dir1.path, "1:dir2/dir3", "1:dir5/and/more"]

        def s2 = updateDir(s1, dir1dir2dir4)
        flatten(s2) == [dir1.path, "1:dir2", "2:dir3", "2:dir4", "1:dir5/and/more"]

        def s3 = updateDir(s2, dir6)
        flatten(s3) == [parent.path, "1:dir1", "2:dir2", "3:dir3", "3:dir4", "2:dir5/and/more", "1:dir6"]

		path       string
		isNil      bool
		size, objs int
		flatten    bool
		oSizes     sizeHistogram
	}{
		{
			path:    "/",
			size:    363515,
			flatten: true,
			objs:    14,
			oSizes:  sizeHistogram{0: 7, 1: 5, 2: 2},
		},
		{
			path:    "/dir1",
			size:    342210,
			objs:    7,
			flatten: false,
			oSizes:  sizeHistogram{0: 2, 1: 3, 2: 2},
		},
		{

    public static <T extends Collection<?>> T flatten(Object[] elements, T addTo, boolean flattenMaps) {
        return flatten(asList(elements), addTo, flattenMaps);
    }

    public static <T extends Collection<?>> T flatten(Object[] elements, T addTo) {
        return flatten(asList(elements), addTo);
    }

    public static <T extends Collection<?>> T flatten(Collection<?> elements, T addTo) {

            } else if (flattenType.isInstance(spec)) {
                flatten = true;
                size += ((CompositeExclude) spec).size();
            } else {
                size++;
            }
        }
        if (!filtered && !flatten) {
            return FlattenOperationResult.of(specs);
        }
        if (filtered && !flatten) {
            return filterOnly(specs, ignoreSpec);
        }

			continue
		}
		pseudoFilename := fmt.Sprintf("%d: generated from %s", i, "default")

		reader := strings.NewReader(string(rj))
		builder = builder.Stream(reader, pseudoFilename)
	}
	r := builder.Flatten().Do()
	if r.Err() != nil {
		return r.Err()
	}
	visitor := genericclioptions.ResourceFinderForResult(r).Do()
	generatedCrds, generatedDeployments, generatedDaemonSets, err := v.verifyPostInstall(
		visitor,

		e := d.Cache[id]
		if len(e.Children) > 0 {
			e = d.flatten(e)
		}
		m[id] = e
	}
	return m
}

// flatten all children of the root into the root element and return it.
func (d *dataUsageCache) flatten(root dataUsageEntry) dataUsageEntry {
	for id := range root.Children {
		e := d.Cache[id]
		if len(e.Children) > 0 {
			e = d.flatten(e)
		}
		root.merge(e)
	}
	root.Children = nil

        collectProblems(childMetadata).empty

        where:
        [parentAnnotation, childAnnotation] << [PROCESSED_PROPERTY_TYPE_ANNOTATIONS, PROCESSED_PROPERTY_TYPE_ANNOTATIONS].combinations()*.flatten()
    }

    def "can override @#processedAnnotation.simpleName property type with @#unprocessedAnnotation.simpleName"() {
        def parentTask = groovyClassLoader.parseClass """

                @TaskAction
                void go() {
                    def file = outputFile.asFile.get()
                    file.text = inputDirs.get()*.asFile*.listFiles().text.flatten().join(',')
                }
            }

            task createDir1(type: DirOutputTask)
            task createDir2(type: DirOutputTask)
            task merge(type: MergeTask) {