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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 stats(self, keys=None, keystats=False):
 """Request server statistics. Fetches stats from each node in the cluster. Without a key specified the server will respond with a default set of statistical information. It returns the a `dict` with stats keys and node-value pairs as a value. :param keys: One or several stats to query :type keys: string or list of string :raise: :exc:`.CouchbaseNetworkError` :return: `dict` where keys are stat keys and values are host-value pairs Find out how many items are in the bucket:: total = 0 for key, value in cb.stats()['total_items'].items():
 total += value Get memory stats (works on couchbase buckets):
: cb.stats('memory') """

        if keys and not isinstance(keys, (tuple, list)):
            keys = (keys,)
        return self._stats(keys, keystats=keystats)