src/vs/workbench/contrib/notebook/browser/services/notebookExecutionStateServiceImpl.ts/NotebookExecutionStateService/_setLastFailedCell
class NotebookExecutionStateService:	private _setLastFailedCell(notebookURI: URI, cellHandle: number): void {
		const prevLastFailedCellInfo = this._lastFailedCells.get(notebookURI);
		const notebook = this._notebookService.getNotebookTextModel(notebookURI);
		if (!notebook) {
			return;
		}

		const newLastFailedCellInfo: IFailedCellInfo = {
			cellHandle: cellHandle,
			disposable: prevLastFailedCellInfo ? prevLastFailedCellInfo.disposable : this._getFailedCellListener(notebook),
			visible: true
		};

		this._lastFailedCells.set(notebookURI, newLastFailedCellInfo);

		this._onDidChangeLastRunFailState.fire({ visible: true, notebook: notebookURI });
	}