protected function getSummaryColumns()
    {
        $columns = [];

        $model = $this->getSampleModel();
        $columnName = $model->getLabelColumnName();

        if ($columnName != "") {
            $columns[] = $columnName;
        }

        return $columns;
    }
protected function getSummaryColumns()
    {
        $columns = [];

        $model = $this->getSampleModel();
        $columnName = $model->getLabelColumnName();

        if ($columnName != "") {
            $columns[] = $columnName;
        }

        return $columns;
    }
protected function getSummaryColumns ( ) { $ columns = [ ] ; $ model = $ this -> getSampleModel ( ) ; $ columnName = $ model -> getLabelColumnName ( ) ; if ( $ columnName != "" ) { $ columns [ ] = $ columnName ; } return $ columns ; }
Override to control the columns returned in HEAD requests

@return string[]
Override to control the columns returned in HEAD requests