primary(_:)
A primary association with a SharePlay group activity that is identified by a given string value.
Declaration
static func primary(_ identifier: String) -> GroupActivityAssociationKindDiscussion
When in an active SharePlay activity, the system will annotate the primary associated scene scene as “shared” and use it as the common scene to arrange spatial Personas around. This association between the group activity and a scene in your app creates a shared space for spatial Personas to interact in.
You should pick an identifier that reflects the content of this view. For example: "in-game", "score-board", or "solar-system-photo.png". Synchronizing the identifier used across all participants in the activity allows FaceTime to synchronize the position of the containing scene.