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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 put_attributes(self, attrs):
 """ Save just these few attributes, not the whole object :param attrs: Attributes to save, key->value dict :type attrs: dict :return: self :rtype: :class:`boto.sdb.db.model.Model` """

        assert(isinstance(attrs, dict)), "Argument must be a dict of key->values to save"
        for prop_name in attrs:
            value = attrs[prop_name]
            prop = self.find_property(prop_name)
            assert(prop), "Property not found: %s" % prop_name
            self._manager.set_property(prop, self, prop_name, value)
        self.reload()
        return self