/**
  * Called if a column does not have a method that provides logic for
  * rendering that column.
  *
  * @param Batch $item
  * @param array $column_name
  * @return string Text or HTML to be placed inside the column.
  */
 public function column_default($item, $column_name)
 {
     switch ($column_name) {
         case 'post_modified':
             return $item->get_modified();
         case 'post_author':
             return $item->get_creator()->get_display_name();
         default:
             return '';
     }
 }
 /**
  * Called if a column does not have a method that provides logic for
  * rendering that column.
  *
  * @param Batch $batch
  * @param array $column_name
  * @return string Text or HTML to be placed inside the column.
  */
 public function column_default($batch, $column_name)
 {
     // Display name of user who created the batch.
     $display_name = '';
     if ($batch->get_creator() !== null) {
         $display_name = $batch->get_creator()->get_display_name();
     }
     switch ($column_name) {
         case 'post_modified':
             return $batch->get_modified();
         case 'post_author':
             return $display_name;
         default:
             return '';
     }
 }