def _get_url(self, url):
        url = str(url)
        if url != 'default' and not '://' in url:
            url = "file:" + urllib.pathname2url(url)
        return url
Returns normalized url. If schema is not given, would fall
dataset/ETHPy150Open codeinn/vcs/vcs/backends/hg/repository.py/MercurialRepository._get_url