def add_url (self, url, line=0, column=0, page=0, name=u"", base=None):
        """If a local webroot directory is configured, replace absolute URLs
        with it. After that queue the URL data for checking."""
        webroot = self.aggregate.config["localwebroot"]
        if webroot and url and url.startswith(u"/"):
            url = webroot + url[1:]
            log.debug(LOG_CHECK, "Applied local webroot `%s' to `%s'.", webroot, url)
        super(FileUrl, self).add_url(url, line=line, column=column, page=page, name=name, base=base)
If a local webroot directory is configured, replace absolute URLs
        with it. After that queue the URL data for checking.