Interactive session

Hello, just an idea I would like to explore.
I would like my users to have the possibility to do an interactive session in a console.

One way I found out how to do this is by just setting the first line of code to be:

```
import pdb; pdb.set_trace()
```

then, users can interactively add whatever they want.
You reckon this is a good idea?

The issue is, that calling the worker always creates a new session and I am not sure how to preserve it and call code withing that session context.

The repro is here:
https://codesandbox.io/s/eager-williams-ly7fxf

Kind regards