src/vs/workbench/api/browser/mainThreadNotebook.ts/MainThreadNotebooks/provideCellStatusBarItems
class MainThreadNotebooks:	async $registerNotebookCellStatusBarItemProvider(handle: number, eventHandle: number | undefined, viewType: string): Promise<void> {
		const that = this;
		const provider: INotebookCellStatusBarItemProvider = {
			async provideCellStatusBarItems(uri: URI, index: number, token: CancellationToken) {
				const result = await that._proxy.$provideNotebookCellStatusBarItems(handle, uri, index, token);
				return {
					items: result?.items ?? [],
					dispose() {
						if (result) {
							that._proxy.$releaseNotebookCellStatusBarItems(result.cacheId);
						}
					}
				};
			},
			viewType
		};

		if (typeof eventHandle === 'number') {
			const emitter = new Emitter<void>();
			this._notebookCellStatusBarRegistrations.set(eventHandle, emitter);
			provider.onDidChangeStatusBarItems = emitter.event;
		}

		const disposable = this._cellStatusBarService.registerCellStatusBarItemProvider(provider);
		this._notebookCellStatusBarRegistrations.set(handle, disposable);
	}