public function renderToggleButton()
    {
        if ($this->toggleButton !== null) {
            $tag   = ArrayHelper::removeValue($this->toggleButton, 'tag', 'button');
            $label = ArrayHelper::removeValue($this->toggleButton, 'label', 'Show');
            if ($tag === 'button' && !isset($this->toggleButton['type'])) {
                $this->toggleButton['type'] = 'button';
            }
            $this->toggleButton['data-reveal-id'] = $this->getId();
            return \CHtml::tag($tag, $this->toggleButton, $label);
        } else {
            return null;
        }
    }