- $screen = get_current_screen();
-
- $columns = get_column_headers( $screen );
- $hidden = get_hidden_columns( $screen );
-
- $_sortable = apply_filters( "manage_{$screen->id}_sortable_columns", $this->get_sortable_columns() );
+ $columns = get_column_headers( $this->screen );
+ $hidden = get_hidden_columns( $this->screen );
+
+ $sortable_columns = $this->get_sortable_columns();
+ /**
+ * Filter the list table sortable columns for a specific screen.
+ *
+ * The dynamic portion of the hook name, $this->screen->id, refers
+ * to the ID of the current screen, usually a string.
+ *
+ * @since 3.5.0
+ *
+ * @param array $sortable_columns An array of sortable columns.
+ */
+ $_sortable = apply_filters( "manage_{$this->screen->id}_sortable_columns", $sortable_columns );