src/vs/workbench/contrib/notebook/browser/contrib/cellStatusBar/contributedStatusBarItemController.ts/ContributedStatusBarItemController/_updateVisibleCells
class ContributedStatusBarItemController:	private _updateVisibleCells(e: {
		added: CellViewModel[];
		removed: { handle: number }[];
	}): void {
		const vm = this._notebookEditor.viewModel;
		if (!vm) {
			return;
		}

		for (let newCell of e.added) {
			const helper = new CellStatusBarHelper(vm, newCell, this._notebookCellStatusBarService);
			this._visibleCells.set(newCell.handle, helper);
		}

		for (let oldCell of e.removed) {
			this._visibleCells.get(oldCell.handle)?.dispose();
			this._visibleCells.delete(oldCell.handle);
		}
	}