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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 torrent_from_url(self, url, cache=True, prefetch=False):
 """Create a Torrent object from a given URL. If the cache option is set, check to see if we already have a Torrent object representing it. If prefetch is set, automatically query the torrent's info page to fill in the torrent object. (If prefetch is false, then the torrent page will be queried lazily on-demand.) """

        if self._use_cache(cache) and url in self._torrent_cache:
            return self._torrent_cache[url]
        torrent = Torrent(url, cache, prefetch)
        if cache:
            self._torrent_cache[url] = torrent
        return torrent