src/vs/workbench/browser/parts/views/treeView.ts/CustomTreeViewDragAndDrop/constructor
class CustomTreeViewDragAndDrop:	constructor(
		private readonly treeId: string,
		@ILabelService private readonly labelService: ILabelService,
		@IInstantiationService private readonly instantiationService: IInstantiationService,
		@ITreeViewsService private readonly treeViewsDragAndDropService: ITreeViewsService,
		@ILogService private readonly logService: ILogService) {
		this.treeMimeType = `application/vnd.code.tree.${treeId.toLowerCase()}`;
	}