src/vs/workbench/api/browser/mainThreadComments.ts/MainThreadCommentController/updateCommentThread
class MainThreadCommentController:	updateCommentThread(commentThreadHandle: number,
		threadId: string,
		resource: UriComponents,
		changes: CommentThreadChanges): void {
		let thread = this.getKnownThread(commentThreadHandle);
		thread.batchUpdate(changes);

		if (thread.isDocumentCommentThread()) {
			this._commentService.updateComments(this._uniqueId, {
				added: [],
				removed: [],
				changed: [thread]
			});
		} else {
			this._commentService.updateNotebookComments(this._uniqueId, {
				added: [],
				removed: [],
				changed: [thread as MainThreadCommentThread<ICellRange>]
			});
		}

	}