src/widget/SmallBox.php
protected function renderHeader()
    {
        if ($this->header !== null) {
            $content = Html::tag('h3', $this->header);
            
            if($this->caption !== NULL){
                $content .= Html::tag('p', $this->caption);
            }
            return Html::tag('div', $content, ['class' => 'inner']);
        } else {
            return null;
        }
    }
protected function renderHeader()
    {
        if ($this->header !== null) {
            $content = Html::tag('h3', $this->header);
            
            if($this->caption !== NULL){
                $content .= Html::tag('p', $this->caption);
            }
            return Html::tag('div', $content, ['class' => 'inner']);
        } else {
            return null;
        }
    }
Renders the header HTML markup of the modal
@return string the rendering result