public String getDataVolumeKMSKeyId() {
        return this.dataVolumeKMSKeyId;
    }
<p>
The ARN of the AWS KMS key for encrypting data at rest. If you don't specify a KMS key, MSK creates one for you
and uses it.
</p>

@return <p>
        The ARN of the AWS KMS key for encrypting data at rest. If you don't specify a KMS key, MSK creates one
        for you and uses it.
        </p>
aws-java-sdk-kafka/src/main/java/com/amazonaws/services/kafka/model/EncryptionAtRest.java