src/vs/base/browser/ui/list/listView.ts/ListView/toDragEvent
class ListView:	private toDragEvent(browserEvent: DragEvent): IListDragEvent<T> {
		const index = this.getItemIndexFromEventTarget(browserEvent.target || null);
		const item = typeof index === 'undefined' ? undefined : this.items[index];
		const element = item && item.element;
		return { browserEvent, index, element };
	}