human
Solve the following python programming problem given the following code:
def _open_config_files(self, command_line_args) : 
    'Tries to parse config file path(s) from within command_line_args.
        Returns a list of opened config files, including files specified on the
        commandline as well as any default_config_files specified in the
        constructor that are present on disk.

        Args:
            command_line_args: List of all args (already split on spaces)
        ' 
    config_files = [open (f) for f in map (os.path.expanduser, self._default_config_files) if os.path.isfile (f)] 
    user_config_file_arg_actions = [a for a in self._actions if getattr (a, 'is_config_file_arg', False)] 
    if (not user_config_file_arg_actions) : 
        return config_files 
for action in user_config_file_arg_actions : 
        arg_parser = argparse.ArgumentParser (prefix_chars = self.prefix_chars, add_help = False) 
        arg_parser._add_action (parsed_arg) 
        def error_method(self, message) : 
            pass 
arg_parser.error = types.MethodType (error_method, arg_parser) 
        parsed_arg = arg_parser.parse_known_args (args = command_line_args) 
        if (not parsed_arg) : 
            continue 
(namespace, _) = parsed_arg 
        user_config_file = getattr (namespace, action.dest, None) 
        if (not user_config_file) : 
            continue 
user_config_file = os.path.expanduser (user_config_file) 
        if (not os.path.isfile (user_config_file)) : 
            self.error (('File not found: %s' % user_config_file)) 
config_files += [open (user_config_file)] 
return config_files 

    
    

    Fix the buggy line: arg_parser._add_action (parsed_arg)
assistant
#Here is Python code to fix the buggy line: arg_parser.

arg_parser._add_action (action)