private function exportColumns()
    {
        return is_array($this->exportColumns) ? $this->toColumnsCollection($this->exportColumns) : $this->getExportColumnsFromBuilder();
    }
private function exportColumns()
    {
        return is_array($this->exportColumns) ? $this->toColumnsCollection($this->exportColumns) : $this->getExportColumnsFromBuilder();
    }
private function exportColumns ( ) { return is_array ( $ this -> exportColumns ) ? $ this -> toColumnsCollection ( $ this -> exportColumns ) : $ this -> getExportColumnsFromBuilder ( ) ; }
Get export columns definition.

@return array|string
Get export columns definition .