Do the completion fields in fine tuning data have implicit stop tokens added to them?

It seems from a small amount of experimentation that they probably do, but this isn’t documented. If so, is there a way to prevent the implicit stop token from being appended to the fine tuning data? That would be helpful in situations where the available fine tuning data is just the beginning of a (potentially longer) synthesis task…

I don’t believe this is done - why do you think so?