public String getLambdaVersion() {
        return this.lambdaVersion;
    }
<p>
The user pool trigger version of the request that Amazon Cognito sends to your Lambda function. Higher-numbered
versions add fields that support new features.
</p>
<p>
You must use a <code>LambdaVersion</code> of <code>V1_0</code> with a custom sender function.
</p>

@return The user pool trigger version of the request that Amazon Cognito sends to your Lambda function.
        Higher-numbered versions add fields that support new features.</p>
        <p>
        You must use a <code>LambdaVersion</code> of <code>V1_0</code> with a custom sender function.
@see CustomEmailSenderLambdaVersionType
aws-java-sdk-cognitoidp/src/main/java/com/amazonaws/services/cognitoidp/model/CustomEmailLambdaVersionConfigType.java