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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 config_value_keys(self, sortkey = False):
 """ Return all mapped configuration keys for this object """

        ret = set()
        cls = type(self)
        while True:
            root = cls.getConfigRoot()
            if root:
                ret = ret.union(set(root.config_value_keys()))
            parent = None
            for c in cls.__bases__:
                if issubclass(c, Configurable):
                    parent = c
            if parent is None:
                break
            cls = parent
        if sortkey:
            return sorted(list(ret))
        else:
            return list(ret)