src/vs/workbench/api/browser/mainThreadComments.ts/MainThreadComments/constructor
class MainThreadComments:	constructor(
		extHostContext: IExtHostContext,
		@ICommentService private readonly _commentService: ICommentService,
		@IViewsService private readonly _viewsService: IViewsService,
		@IViewDescriptorService private readonly _viewDescriptorService: IViewDescriptorService
	) {
		super();
		this._proxy = extHostContext.getProxy(ExtHostContext.ExtHostComments);

		this._register(this._commentService.onDidChangeActiveCommentThread(async thread => {
			let handle = (thread as MainThreadCommentThread).controllerHandle;
			let controller = this._commentControllers.get(handle);

			if (!controller) {
				return;
			}

			this._activeCommentThreadDisposables.clear();
			this._activeCommentThread = thread as MainThreadCommentThread;
			controller.activeCommentThread = this._activeCommentThread;
		}));
	}