@Override
    public String convertTo(SortedSet<Path> value) {
        if (value == null) {
            throw new ParameterException("String list of Paths must not be null.");
        }

        return value.stream().map(Path::toString).collect(Collectors.joining(","));
    }
@Test
    public void testConvertTo() {
        TreeSet<Path> sortedSet = new TreeSet<>(Comparator.comparing(Path::toString));
        sortedSet.add(Paths.get("/some-dir"));
        sortedSet.add(Paths.get("/Z-dir"));
        sortedSet.add(Paths.get("/z-dir"));
        sortedSet.add(Paths.get("/another-dir/sub"));
        sortedSet.add(Paths.get("/another-dir"));
        assertEquals("/Z-dir,/another-dir,/another-dir/sub,/some-dir,/z-dir", converter.convertTo(sortedSet));
    }