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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 get(self, item, cache=None):
 """Lookup a torrent info property. If cache is True, check the cache first. If the cache is empty, then fetch torrent info before returning it. """

        if item not in self._keys:
            raise KeyError(item)
        if self._use_cache(cache) and (self._fetched or
                item in self._attrs):
            return self._attrs[item]
        info = self.fetch(cache=cache)
        return info[item]