public String getOperationId() {
        return this.operationId;
    }
<p>
The unique ID for this stack set operation.
</p>
<p>
The operation ID also functions as an idempotency token, to ensure that CloudFormation performs the stack set
operation only once, even if you retry the request multiple times. You might retry stack set operation requests
to ensure that CloudFormation successfully received them.
</p>
<p>
If you don't specify an operation ID, CloudFormation generates one automatically.
</p>
<p>
Repeating this stack set operation with a new operation ID retries all stack instances whose status is
<code>OUTDATED</code>.
</p>

@return The unique ID for this stack set operation.</p>
        <p>
        The operation ID also functions as an idempotency token, to ensure that CloudFormation performs the stack
        set operation only once, even if you retry the request multiple times. You might retry stack set
        operation requests to ensure that CloudFormation successfully received them.
        </p>
        <p>
        If you don't specify an operation ID, CloudFormation generates one automatically.
        </p>
        <p>
        Repeating this stack set operation with a new operation ID retries all stack instances whose status is
        <code>OUTDATED</code>.
aws-java-sdk-cloudformation/src/main/java/com/amazonaws/services/cloudformation/model/UpdateStackSetRequest.java