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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 process_request(self, request):
 """ Sets the current request's ``urlconf`` attribute to the urlconf associated with the subdomain, if it is listed in ``settings.SUBDOMAIN_URLCONFS``. """

        super(SubdomainURLRoutingMiddleware, self).process_request(request)

        subdomain = getattr(request, 'subdomain', UNSET)

        if subdomain is not UNSET:
            urlconf = settings.SUBDOMAIN_URLCONFS.get(subdomain)
            if urlconf is not None:
                logger.debug("Using urlconf %s for subdomain: %s",
                    repr(urlconf), repr(subdomain))
                request.urlconf = urlconf