protected function _normalizeTableColumns($columns)
    {
        $_defaults = [
            'get' => false,
            'before' => '',
            'after' => '',
        ];
        $result = [];

        foreach ($columns as $name => $options) {
            if (is_array($options)) {
                $_defaults['get'] = $name;
                $result[$name] = array_merge($_defaults, $options);
            } else {
                $_defaults['get'] = $options;
                $result[$options] = $_defaults;
            }
        }
        return $result;
    }