public function _list($patterns, $assoc_args)
    {
        $this->init_args(func_get_args());
        $env   = $this->get_env_for_read_or_fail();

        $items = $env->dictionaryWithKeysMatching($patterns)
            ->map(function ($value, $key) {
                return (object) compact('key', 'value');
            });

        $args      = $this->args->toArray(); // var required - passed by reference
        $formatter = new Formatter($args, $this->fields());
        $formatter->display_items($items->all());
    }