src/vs/workbench/contrib/notebook/browser/viewModel/notebookViewModelImpl.ts/NotebookViewModel/deltaCellStatusBarItems
class NotebookViewModel:	deltaCellStatusBarItems(oldItems: string[], newItems: INotebookDeltaCellStatusBarItems[]): string[] {
		const deletesByHandle = groupBy(oldItems, id => this._statusBarItemIdToCellMap.get(id) ?? -1);

		const result: string[] = [];
		newItems.forEach(itemDelta => {
			const cell = this.getCellByHandle(itemDelta.handle);
			const deleted = deletesByHandle[itemDelta.handle] ?? [];
			delete deletesByHandle[itemDelta.handle];
			const ret = cell?.deltaCellStatusBarItems(deleted, itemDelta.items) || [];
			ret.forEach(id => {
				this._statusBarItemIdToCellMap.set(id, itemDelta.handle);
			});

			result.push(...ret);
		});

		for (const _handle in deletesByHandle) {
			const handle = parseInt(_handle);
			const ids = deletesByHandle[handle];
			const cell = this.getCellByHandle(handle);
			cell?.deltaCellStatusBarItems(ids, []);
		}

		return result;
	}