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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 __driver_stub(self, text, state):
 """Display help messages or invoke the proper completer. The interface of helper methods and completer methods are documented in the helper() decorator method and the completer() decorator method, respectively. Arguments: text: A string, that is the current completion scope. state: An integer. Returns: A string used to replace the given text, if any. None if no completion candidates are found. Raises: This method is called via the readline callback. If this method raises an error, it is silently ignored by the readline library. This behavior makes debugging very difficult. For this reason, non-driver methods are run within try-except blocks. When an error occurs, the stack trace is printed to self.stderr. """

        origline = readline.get_line_buffer()
        line = origline.lstrip()
        if line and line[-1] == '?':
            self.__driver_helper(line)
        else:
            toks = shlex.split(line)
            return self.__driver_completer(toks, text, state)