public static String makeSafeName(final String string) {
        return NullSafe.get(string, str ->
                SAFE_NAME_PATTERN.matcher(string)
                        .replaceAll("_"));
    }
Extract the number represented by the supplied `0` padded string.

@param string A directory name.
@return The long part of the string if found, else empty.
stroom-proxy/stroom-proxy-app/src/main/java/stroom/proxy/app/handler/DirUtil.java