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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_cached_response(self, request, response):
 """On a 304 we will get a new set of headers that we want to update our cached value with, assuming we have one. This should only ever be called when we've sent an ETag and gotten a 304 as the response. """

        cache_url = self.cache_url(request.url)

        cached_response = self.serializer.loads(request, self.cache.get(cache_url))

        if not cached_response:
            # we didn't have a cached response
            return response

        # Lets update our headers with the headers from the new request:
        # http://tools.ietf.org/html/draft-ietf-httpbis-p4-conditional-26#section-4.1
        #
        # The server isn't supposed to send headers that would make
        # the cached body invalid. But... just in case, we'll be sure
        # to strip out ones we know that might be problmatic due to
        # typical assumptions.
        excluded_headers = ["content-length"]

        cached_response.headers.update(
            dict(
                (k, v)
                for k, v in response.headers.items()
                if k.lower() not in excluded_headers
            )
        )

        # we want a 200 b/c we have content via the cache
        cached_response.status = 200

        # update our cache
        self.cache.set(cache_url, self.serializer.dumps(request, cached_response))

        return cached_response