in pekko-sample-persistence-scala/src/main/scala/sample/persistence/ShoppingCart.scala [204:212]
private def handleEvent(state: State, event: Event) = {
event match {
case ItemAdded(_, itemId, quantity) => state.updateItem(itemId, quantity)
case ItemRemoved(_, itemId) => state.removeItem(itemId)
case ItemQuantityAdjusted(_, itemId, quantity) =>
state.updateItem(itemId, quantity)
case CheckedOut(_, eventTime) => state.checkout(eventTime)
}
}