CommittedEvent
class CommittedEvent @InternalWowApi constructor(val name: String, val revision: Int, val body: Any)
One event of an EventStream: its name and revision as the model reads it now (upgraded) and its body, masked as the Manifest declares: an instance of the model's event class, or a Map of an event the reader has no class for. The commit a sourcing function reads holds the events as the model's classes, unmasked.
Fields may be added: construct one with of; the constructor is internal to Wow.