src/vs/base/browser/ui/list/listWidget.ts/ListViewDragAndDrop/onDragStart
class ListViewDragAndDrop:	onDragStart(data: IDragAndDropData, originalEvent: DragEvent): void {
		if (this.dnd.onDragStart) {
			this.dnd.onDragStart(data, originalEvent);
		}
	}