ExpandRowColumn - Cannot use object of type Closure as array

[Shin1gami]

As the doc says $detailOptions can be either array or Closure, so passing an anonymous function like this:

'detailOptions' => function($model) {
    return ['data' => ['something' => $model->something]];
}

Causes exception:

exception 'yii\base\ErrorException' with message
'Cannot use object of type Closure as array'
in /srv/www/ds3/vendor/yiisoft/yii2/helpers/BaseHtml.php:1705

I guess it's beacuse of Html::addCssClass($this->detailOptions, 'skip-export'); (row 223)