/**
* Renders the header cell.
*/
public function renderHeaderCell()
{
if ($this->grid->filterModel !== null && $this->mergeHeader && $this->grid->filterPosition === GridView::FILTER_POS_BODY) {
$this->headerOptions['rowspan'] = 2;
Html::addCssClass($this->headerOptions, 'kv-merged-header');
}
return parent::renderHeaderCell();
}
