An event handler is a function that applies a persisted event to an actor’s current state, producing the next state during processing or recovery replay. In EventSourcedBehavior, it works with the persistence ID, initial state, and command handler. section 9.2.1
Cargo container state
A persistent cargo container can represent its state as a list of cargo items and its events as CargoAdded values. The event handler turns each persisted event into the updated State.
