src/vs/workbench/browser/parts/views/treeView.ts/CustomTreeViewDragAndDrop/drop
class CustomTreeViewDragAndDrop:	async drop(data: IDragAndDropData, targetNode: ITreeItem | undefined, targetIndex: number | undefined, originalEvent: DragEvent): Promise<void> {
		if (data instanceof ElementsDragAndDropData) {
			const elements = data.elements;
			if (targetNode) {
				await this.dndController.onDrop(elements, targetNode);
			}
		}
	}