public void setMasterUserARN(String masterUserARN) {
        this.masterUserARN = masterUserARN;
    }
<p>
Amazon Resource Name (ARN) for the master user. Only specify if <code>InternalUserDatabaseEnabled</code> is
<code>false</code>.
</p>

@param masterUserARN
       Amazon Resource Name (ARN) for the master user. Only specify if <code>InternalUserDatabaseEnabled</code>
       is <code>false</code>.
aws-java-sdk-opensearch/src/main/java/com/amazonaws/services/opensearch/model/MasterUserOptions.java