Cómo invocar una función de AWS Lambda de manera asincrónica

AWSLambdaAsyncClient client = new AWSLambdaAsyncClient();
client.withRegion(Regions.fromName(region));
InvokeRequest request = new InvokeRequest();
request.setInvocationType("Event");
request.withFunctionName(functionName).withPayload(payload);
InvokeResult invoke = client.invoke(request);
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