Nette\Forms\Controls\ChoiceControl::setItems PHP Method

    public function setItems(array $items, $useKeys = TRUE)
    {
        $this->items = $useKeys ? $items : array_combine($items, $items);
        return $this;
    }

 /**
  * Sets options and option groups from which to choose.
  * @return self
  */
 public function setItems(array $items, $useKeys = TRUE)
 {
     if (!$useKeys) {
         foreach ($items as $key => $value) {
             unset($items[$key]);
             if (is_array($value)) {
                 foreach ($value as $val) {
                     $items[$key][(string) $val] = $val;
                 }
             } else {
                 $items[(string) $value] = $value;
             }
         }
     }
     $this->options = $items;
     return parent::setItems(Nette\Utils\Arrays::flatten($items, TRUE));
 }