How to determine if a Notebook has cell errors

I am writing a New Relic Synthetic which opens and runs a Notebook. I block until Jupyter.notebook.kernel_busy is false. Now I need to know if the notebook completed successfully with NO errors in any cells. Is there such a boolean or status or event or ??? I can monitor to determine success?

Start with the Jupyter.notebook.kernel_busy API mentioned in the issue and trace how notebook cell execution reports errors or completion. Determine whether an existing status, event, or boolean can reliably indicate that all cells succeeded; done means documenting or defining a clear success signal for this automation use case.

Written by the indexing model from the issue text.