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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 set_many(self, mapping, timeout=None):
 """Sets multiple keys and values from a mapping. :param mapping: a mapping with the keys/values to set. :param timeout: the cache timeout for the key (if not specified, it uses the default timeout). """

        for key, value in _items(mapping):
            self.set(key, value, timeout)