public void setDefaultOnly(Boolean defaultOnly) {
        this.defaultOnly = defaultOnly;
    }
<p>
Indicates that only the default version of the specified engine or engine and major version combination is
returned.
</p>

@param defaultOnly
       Indicates that only the default version of the specified engine or engine and major version combination is
       returned.
aws-java-sdk-neptune/src/main/java/com/amazonaws/services/neptune/model/DescribeDBEngineVersionsRequest.java