NewMessageEventHandlerImpl
constructor(proteusMessageUnpacker: ProteusMessageUnpacker, mlsMessageUnpacker: MLSMessageUnpacker, applicationMessageHandler: ApplicationMessageHandler, legalHoldHandler: LegalHoldHandler, enqueueSelfDeletion: (<Error class: unknown class>, messageId: String) -> Unit, enqueueConfirmationDelivery: suspend (<Error class: unknown class>, messageId: String) -> Unit, selfUserId: <Error class: unknown class>, staleEpochVerifier: StaleEpochVerifier)