我有一个aws lambda函数，如下所示：

class FooHandler: RequestHandler<APIGatewayProxyRequestEvent, APIGatewayProxyResponseEvent> {
    
        private val lambdaClient = LambdaClient.create()
        private val logger = LogManager.getLogger(CollectorHandler::class)
    
        override fun handleRequest(request: APIGatewayProxyRequestEvent, context: Context): APIGatewayProxyResponseEvent {
    
            val response = APIGatewayProxyResponseEvent()
    
            if (isRequiredHeaderEmpty(request, response) || isBodyEmpty(request, response)) {
                return response
            }
return response

我正在使用MockK编写aws lambda的单元测试。下面是测试类：

class FooHandlerTest {

    private val request = APIGatewayProxyRequestEvent()
    private var response = APIGatewayProxyResponseEvent()
    @SpyK
    private lateinit var handler: FooHandler
    @MockK
    private lateinit var lambdaClient: LambdaClient
    @MockK
    private lateinit var context: Context

    @BeforeTest
    fun setUp() {

        handler = spyk()
        lambdaClient = mockk()
        context = mockk()
    }

    @Test
    fun testHandleRequestWhenBodyIsEmpty(){

        request.body=""
        response = handler.handleRequest(request, context)
        expectThat(response.statusCode).isEqualTo(HttpStatus.BAD_REQUEST)

    }

当我运行测试时，我得到了以下错误：
io.mockk.MockKException:无法通过类FooHandler的默认构造函数示例化代理
当我进一步查看时，它也给出了以下错误：原因：软件。亚马逊。awssdk。核心。异常。SdkClientException：无法从链软件中的任何提供程序加载区域。amazon.awssdk.regions.providers.DefaultAwsRegionProviderChain@7668d560
看起来它没有在模仿LambdaClient，而是在调用实际的函数。我知道如何可靠地测试我的处理函数吗？