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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def dav_index(context, data):
 """List files in a WebDAV directory."""

    # This is made to work with ownCloud/nextCloud, but some rumor has
    # it they are "standards compliant" and it should thus work for
    # other DAV servers.
    url = data.get('url')
    result = context.http.request('PROPFIND', url)
    for resp in result.xml.findall('./{DAV:}response'):
        href = resp.findtext('./{DAV:}href')
        if href is None:
            continue

        rurl = urljoin(url, href)
        rdata = data.copy()
        rdata['url'] = rurl
        rdata['foreign_id'] = rurl
        if rdata['url'] == url:
            continue

        if resp.find('.//{DAV:}collection') is not None:
            rdata['parent_foreign_id'] = rurl
            context.log.info("Fetching contents of folder: %s" % rurl)
            context.recurse(data=rdata)
        else:
            rdata['parent_foreign_id'] = url

        # Do GET requests on the urls
        fetch(context, rdata)