public async Task ShouldStopSendingHeartbeatsToTheTxWorker( uint interval, int sequenceNumber, [Frozen] ITimer heartbeat, [Frozen, Substitute] IGatewayUtilsFactory factory, [Frozen, Substitute] IGatewayTxWorker txWorker, [Frozen, Substitute] ITimerFactory timerFactory, [Target] DefaultGatewayService gateway ) { gateway.SequenceNumber = sequenceNumber; await gateway.StartAsync(); await gateway.StartHeartbeat(interval); await gateway.StopHeartbeat(); await heartbeat.Received().Stop(); }