### Question:
IotCoreClient { public void publishDeviceState(byte[] state) { if (mUnsentDeviceState.getAndSet(state) == null) { mSemaphore.release(); } } private  IotCoreClient(
            @NonNull ConnectionParams connectionParams,
            @NonNull KeyPair keyPair,
            @NonNull MqttClient mqttClient,
            @NonNull Queue<TelemetryEvent> telemetryQueue,
            @Nullable Executor connectionCallbackExecutor,
            @Nullable ConnectionCallback connectionCallback,
            @Nullable Executor onConfigurationExecutor,
            @Nullable OnConfigurationListener onConfigurationListener,
            @Nullable Executor onCommandExecutor,
            @Nullable OnCommandListener onCommandListener); @VisibleForTesting  IotCoreClient(
            @NonNull ConnectionParams configuration,
            @NonNull MqttClient mqttClient,
            @NonNull JwtGenerator jwtGenerator,
            @NonNull AtomicBoolean runBackgroundThread,
            @NonNull AtomicReference<byte[]> unsentDeviceState,
            @NonNull Queue<TelemetryEvent> telemetryQueue,
            @Nullable Executor connectionCallbackExecutor,
            @Nullable ConnectionCallback connectionCallback,
            @Nullable Executor onConfigurationExecutor,
            @Nullable OnConfigurationListener onConfigurationListener,
            @Nullable Executor onCommandExecutor,
            @Nullable OnCommandListener onCommandListener,
            @NonNull Semaphore semaphore,
            @NonNull BoundedExponentialBackoff backoff,
            @NonNull AtomicBoolean clientConnectionState); void connect(); boolean isConnected(); void disconnect(); boolean publishTelemetry(@NonNull TelemetryEvent event); void publishDeviceState(byte[] state);  }### Answer:
@Test public void testPublishDeviceState() { mTestIotCoreClient.publishDeviceState(DATA); assertThat(mUnsentDeviceStateSpy.get()).isEqualTo(DATA); verify(mMockSemaphore).release(); }
@Test public void testPublishDeviceStateExistingData() { mUnsentDeviceStateSpy.set("existing".getBytes()); mTestIotCoreClient.publishDeviceState(DATA); assertThat(mUnsentDeviceStateSpy.get()).isEqualTo(DATA); verify(mMockSemaphore, never()).release(); }