src/vs/workbench/contrib/notebook/browser/contrib/cellStatusBar/notebookVisibleCellObserver.ts/NotebookVisibleCellObserver/updateEverything
class NotebookVisibleCellObserver:	protected updateEverything(): void {
		this._onDidChangeVisibleCells.fire({ added: [], removed: Array.from(this._visibleCells) });
		this._visibleCells = [];
		this._updateVisibleCells();
	}