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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 update(url):
 """ Update remote DNS record by requesting its special endpoint URL. This automatically picks the IP address using the HTTP connection: it is not possible to specify the IP address explicitly. :param url: URL to retrieve for triggering the update :return: IP address """

    req = requests.get(
        url, headers=constants.REQUEST_HEADERS_DEFAULT, timeout=60)
    req.close()
    # Response must contain an IP address, or else we can't parse it.
    # Also, the IP address in the response is the newly assigned IP address.
    ipregex = re.compile(r"\b(?P<ip>(?:[0-9]{1,3}\.){3}[0-9]{1,3})\b")
    ipmatch = ipregex.search(req.text)
    if ipmatch:
        return str(ipaddress(ipmatch.group("ip")))
    LOG.error("couldn't parse the server's response '%s'", req.text)
    return None