ActiveField.php
public function radioListWithGap($items, $options = [])
    {
        $this->addListInputCssClass($options, $this->radioGapCssClass);
        return self::radioList($items, $options);
    }
public function radioListWithGap($items, $options = [])
    {
        $this->addListInputCssClass($options, $this->radioGapCssClass);
        return self::radioList($items, $options);
    }
Renders a list of radio buttons with gap
@param $items
@param array $options
@return $this|ActiveField