src/vs/workbench/contrib/notebook/common/notebookEditorModel.ts/NotebookFileWorkingCopyModel/update
class NotebookFileWorkingCopyModel:	async update(stream: VSBufferReadableStream, token: CancellationToken): Promise<void> {

		const bytes = await streamToBuffer(stream);
		const data = await this._notebookSerializer.dataToNotebook(bytes);

		if (token.isCancellationRequested) {
			throw canceled();
		}
		this._notebookModel.reset(data.cells, data.metadata, this._notebookSerializer.options);
	}