protected function _getBtnClass(array $options = [])
    {
        if (Arr::key('button', $options)) {
            $button = $options['button'];
            unset($options['button']);

            if (is_callable($this->getConfig('prepareBtnClass'))) {
                return (array) call_user_func($this->getConfig('prepareBtnClass'), $this, $options, $button);
            }

            $options = $this->_setBtnClass($button, $options);
        }

        return $options;
    }