public Path get() throws IOException {
        final long id = sequence.incrementAndGet();
        final String name = create(id);
        final Path path = parentDir.resolve(name);
        return Files.createDirectory(path);
    }
Gets a new numbered directory with a number one higher than the last one issued.
stroom-proxy/stroom-proxy-app/src/main/java/stroom/proxy/app/handler/NumberedDirProvider.java