public IPSetSummary withLockToken(String lockToken) {
        setLockToken(lockToken);
        return this;
    }
<p>
A token used for optimistic locking. WAF returns a token to your <code>get</code> and <code>list</code> requests,
to mark the state of the entity at the time of the request. To make changes to the entity associated with the
token, you provide the token to operations like <code>update</code> and <code>delete</code>. WAF uses the token
to ensure that no changes have been made to the entity since you last retrieved it. If a change has been made,
the update fails with a <code>WAFOptimisticLockException</code>. If this happens, perform another
<code>get</code>, and use the new token returned by that operation.
</p>

@param lockToken
       A token used for optimistic locking. WAF returns a token to your <code>get</code> and <code>list</code>
       requests, to mark the state of the entity at the time of the request. To make changes to the entity
       associated with the token, you provide the token to operations like <code>update</code> and
       <code>delete</code>. WAF uses the token to ensure that no changes have been made to the entity since you
       last retrieved it. If a change has been made, the update fails with a
       <code>WAFOptimisticLockException</code>. If this happens, perform another <code>get</code>, and use the
       new token returned by that operation.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-wafv2/src/main/java/com/amazonaws/services/wafv2/model/IPSetSummary.java