src/vs/workbench/contrib/interactive/browser/interactiveEditorInput.ts/InteractiveEditorInput/_serializeNotebook
class InteractiveEditorInput:	private _serializeNotebook(notebook?: NotebookTextModel) {
		if (!notebook) {
			return undefined;
		}

		const cells = notebook.cells.map(cell => serializeCell(cell));

		return {
			cells: cells,
			metadata: notebook.metadata,
			transientOptions: notebook.transientOptions
		};
	}