protected function getListField($folderID)
 {
     $field = parent::getListField($folderID);
     $fileField = $field->FieldList()->dataFieldByName('Files');
     $columns = $fileField->getConfig()->getComponentByType('GridFieldDataColumns');
     $columns->setDisplayFields(array('StripThumbnail' => '', 'Title' => _t('File.Name'), 'Created' => _t('AssetAdmin.CREATED', 'Date'), 'Size' => _t('AssetAdmin.SIZE', 'Size')));
     return $field;
 }
 protected function getListField($folderID)
 {
     $list = parent::getListField($folderID);
     // update with icons & filenames including extensions
     $ext = new AssetAdmin_IconExtension();
     $ext->updateEditForm($list);
     return $list;
 }