public function getModalCss(Vtiger_Request $request)
{
$parentCssInstances = parent::getModalCss($request);
$cssFileNames = ['~libraries/jquery/jstree/themes/proton/style.css'];
$modalInstances = $this->checkAndConvertCssStyles($cssFileNames);
$cssInstances = array_merge($modalInstances, $parentCssInstances);
return $cssInstances;
}