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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 flush(cls, *args):
 """ Removes all keys of this namespace Without args, clears all keys starting with cls.PREFIX if called with args, clears keys starting with given cls.PREFIX + args Args: *args: Arbitrary number of arguments. Returns: List of removed keys. """

        return _remove_keys([], [(cls._make_key(args) if args else cls.PREFIX) + '*'])