IPCondition.clone() always return null

/**
 * Returns a copy of this object.
 *
 * @return a copy of this object
 */
public Object clone() {
    IPCondition theClone = null;
    if(ipv4){
        iPv4ConditionInstance.clone();
    }else if(ipv6){
        iPv6ConditionInstance.clone();
    }
    return theClone;
}