/**
* Renders a list of checkboxes.
* A checkbox list allows multiple selection, like [[listBox()]].
* As a result, the corresponding submitted value is an array.
* The selection of the checkbox list is taken from the value of the model attribute.
* @param array $items the data item used to generate the checkboxes.
* The array values are the labels, while the array keys are the corresponding checkbox values.
* @param array $options options (name => config) for the checkbox list.
* For the list of available options please refer to the `$options` parameter of [[\yii\helpers\Html::activeCheckboxList()]].
* @return $this the field object itself
*/
public function checkboxList($items, $options = [])
{
$this->adjustLabelFor($options);
$this->parts['{input}'] = Html::activeCheckboxList($this->model, $this->attribute, $items, $options);
return $this;
}