message: Set the drag image used when dragging tabs
diff: @@ -475,6 +475,9 @@ export class TabWidget extends ThemeableElementBase {
  }
  ev.dataTransfer.setData(MIMETYPE_ELEMENT, parentElement.id);
  + ev.dataTransfer.setDragImage(parentElement, -10, -10);
  + ev.dataTransfer.effectAllowed = 'move';
  + ev.dataTransfer.dropEffect = 'move';
  }
  private _handleDragEnter(ev: DragEvent): void {
  