PeerCommand
class PeerCommand(val name: String, val type: Class<*>?, val creation: Creation, val idProperty: String? = null)
A command type of a peer context's contract: its full name (ctx.agg.Command), its class, when on the class path (type), whether it creates its aggregate (creation), and the property of its body that holds its aggregate's id (idProperty; null for one whose request names it).