public void setDomainName(String domainName) {
        this.domainName = domainName;
    }
<p>
Name of the OpenSearch Service domain that you want to upgrade.
</p>

@param domainName
       Name of the OpenSearch Service domain that you want to upgrade.
aws-java-sdk-opensearch/src/main/java/com/amazonaws/services/opensearch/model/UpgradeDomainRequest.java