How to use the justext._compat.URLError function in jusText

if stoplist is None:
            raise JustextInvalidOptions("No stoplist specified.")

        if not stoplist:
            # empty stoplist, switch to language-independent mode
            stopwords_high = 0
            stopwords_low = 0

        if args:
            try:
                if re.match(r"[^:/]+://", args[0]):
                    fp_in = urllib.urlopen(args[0])
                else:
                    fp_in = open(args[0], 'r')
            except (IOError, URLError) as e:
                raise JustextInvalidOptions(
                    "Can't open %s for reading: %s" % (args[0], e))
                sys.exit(1)

        html_text = fp_in.read()
        if fp_in is not sys.stdin:
            fp_in.close()

        paragraphs = justext(html_text, stoplist, length_low, length_high,
            stopwords_low, stopwords_high, max_link_density, max_heading_distance,
            no_headings, encoding, default_encoding, enc_errors)
        if format == "default":
            output_default(paragraphs, fp_out)
        elif format == "boilerplate":
            output_default(paragraphs, fp_out, no_boilerplate=False)
        elif format == "detailed":