How can I access the HKMetadataKeySwimmingStrokeStyle enum?

I'm looking at a swimming workout sample and in the metadata I see:

Optional(["HKIndoorWorkout": 0, "HKSwimmingLocationType": 2, "HKAverageMETs": 10.7366 kcal/hr·kg, "HKTimeZone": America/New_York])

There is no mention of the HKMetadataKeySwimmingStrokeStyle yet when I look at the workout in the Apple Fitness app, there is stroke style data.

How can I access the stroke enum?

How can I access the HKMetadataKeySwimmingStrokeStyle enum?
 
 
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