How do you model smoking status in Phenopackets?

From GA4GH Slack:

> I am looking into phenopackets and trying to figure out how I would model smoking status. I can see on the documentation website that there is a reference to an 'Exposure' object being included in version 2, https://phenopacket-schema.readthedocs.io/en/latest/version2.html and https://phenopacket-schema.readthedocs.io/en/latest/exposure.html but I don't see this in the schema diagrams or the building blocks, and not sure how it would be packaged in a phenopacket. Anyone know any more or whether there is an accepted way of modelling patient smoking status in phenopackets?