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

        return Arrays.stream(value.split(SEPARATOR))
                     .map(StringUtils::trimToNull)
                     .filter(Objects::nonNull)
                     .map(Paths::get)
                     .collect(Collectors.toCollection(sortedPathSupplier()));
    }
@Test(expected = ParameterException.class)
    public void testConvertFromNull() {
        converter.convertFrom(null);
    }