function dropTargetForExternal(args) {
  // not removing unused events, just leaning on the type system
  return adapter.dropTarget(args);
}
Some events don't make sense for the external adapter

`onGenerateDragPreview`
The browser creates the drag preview for external drags, so we don't
need an event to generate the preview for _monitors_ or the _dropTarget_

`onDragStart`
An external drag can never start from in the `window`, so _dropTarget_'s
don't need `onDragStart`