lib/components/web/widgets/decorator/PanelDecorator.php
public function generateHeader()
    {
        $parts = [];
        $title = $this->owner->generatePanelTitle();
        if ($title) {
            $parts[] = $title;
        }
        $parts[] = Html::beginTag('div', ['class' => 'panel-body']);

        return implode("", $parts);
    }
public function generateHeader()
    {
        $parts = [];
        $title = $this->owner->generatePanelTitle();
        if ($title) {
            $parts[] = $title;
        }
        $parts[] = Html::beginTag('div', ['class' => 'panel-body']);

        return implode("", $parts);
    }
[[@doctodo method_description:generateHeader]].

@return [[@doctodo return_type:generateHeader]] [[@doctodo return_description:generateHeader]]