}
        return null;
    }

    @Nonnull
    public static Path findMandatoryRoot(Path topDirectory) {
        requireNonNull(topDirectory, "topDirectory");
        return getCanonicalPath(Optional.ofNullable(
                        ServiceLoader.load(RootLocator.class).iterator().next().findMandatoryRoot(topDirectory))
                .orElseThrow());
    }