fun FileSystemOperations.removeOldVersionsFromDir(dir: Directory, shouldDelete: Spec<GradleVersion>, dirPrefix: String = "", dirSuffix: String = "") {
    if (dir.asFile.isDirectory) {
        for (cacheDir in dir.asFile.listFiles()) {
            val cacheDirName = cacheDir.name
            if (!cacheDirName.startsWith(dirPrefix) || !cacheDirName.endsWith(dirSuffix)) {
                continue
            }

        Path dir = fs.getPath("dir");
        assertEquals(6, MoreFiles.listFiles(dir).size());

        method.delete(dir);
        method.assertDeleteSucceeded(dir);

        assertEquals(
            "contents of /dontdelete deleted by delete method " + method,
            3,
            MoreFiles.listFiles(fs.getPath("/dontdelete")).size());
      }
    }
  }

        Path dir = fs.getPath("dir");
        assertEquals(6, MoreFiles.listFiles(dir).size());

        method.delete(dir);
        method.assertDeleteSucceeded(dir);

        assertEquals(
            "contents of /dontdelete deleted by delete method " + method,
            3,
            MoreFiles.listFiles(fs.getPath("/dontdelete")).size());
      }
    }
  }

        val subprojectRoots = File("../platforms").listFiles(File::isDirectory).plus(File("../subprojects"))
        val subProjectFolders = subprojectRoots.map { it.listFiles(File::isDirectory).asList() }.flatten().filter { dir ->
            // filter out the directories that have only a `build` subdirectory - this usually happens after branch switching
            dir.listFiles { _: File, name: String -> name != "build" }!!.isNotEmpty()
        }

            return new File[0];
        }
        final File libDir = new File(libPath);
        if (!libDir.exists()) {
            return new File[0];
        }
        return libDir.listFiles((file, name) -> name.startsWith(namePrefix));
    }

    public static File[] getPluginJarFiles(final String namePrefix) {
        return getPluginJarFiles((file, name) -> name.startsWith(namePrefix));
    }

            if (hasCleaned) {
                return
            }
            logger.lifecycle("Cleaning up caches...")
            val homeDir = parameters.homeDir.get()

            homeDir.asFile.listFiles()?.filter { it.name.startsWith("distributions-") }?.forEach {
                val workerDir = homeDir.dir(it.name)
                cleanupDistributionCaches(workerDir, GradleVersion.version(parameters.gradleVersion.get()))

        final List<File> fileList = new ArrayList<>(
                FileUtils.listFiles(new File(baseDir, "images"), fessConfig.getSupportedUploadedMediaExtentionsAsArray(), true));
        fileList.addAll(FileUtils.listFiles(new File(baseDir, "css"), fessConfig.getSupportedUploadedCssExtentionsAsArray(), true));
        fileList.addAll(FileUtils.listFiles(new File(baseDir, "js"), fessConfig.getSupportedUploadedJsExtentionsAsArray(), true));

    @InputDirectory
    abstract DirectoryProperty getJsonFileDirectory()

    @TaskAction
    void clean() {
        def jsonFileManager = new AcceptedApiChangesJsonFileManager()
        jsonFileDirectory.asFile.get().listFiles()
            ?.findAll { it.name.endsWith(".json") }
            ?.each { jsonFileManager.emptyAcceptedApiChanges(it) }
    }

    abstract val apiChangesDirectory: DirectoryProperty

    protected
    fun loadChanges(): Map<File, List<AcceptedApiChange>> {
        return apiChangesDirectory.get().asFile.listFiles()
            ?.filter {
                it.name.endsWith(".json")
            }?.associate {
                it to it.readAcceptedChanges()
            }?.filterValues {
                it.acceptedApiChanges != null

                final Set<RequestData> requestDataSet = new HashSet<>();
                if (includeContent) {
                    try {
                        final FTPFile[] files = client.listFiles(ftpInfo.getParent(), FTPFileFilters.NON_NULL);
                        validateRequest(client);
                        for (final FTPFile f : files) {