code: def flush(cls, *args):
          
          return _remove_keys([], [(cls._make_key(args) if args else cls.PREFIX) + '*'])
docs: 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.