public Boolean isActive() {
        return this.active;
    }
<p>
When <code>true</code>, StackSets performs non-conflicting operations concurrently and queues conflicting
operations. After conflicting operations finish, StackSets starts queued operations in request order.
</p>
<note>
<p>
If there are already running or queued operations, StackSets queues all incoming operations even if they are
non-conflicting.
</p>
<p>
You can't modify your stack set's execution configuration while there are running or queued operations for that
stack set.
</p>
</note>
<p>
When <code>false</code> (default), StackSets performs one operation at a time in request order.
</p>

@return When <code>true</code>, StackSets performs non-conflicting operations concurrently and queues conflicting
        operations. After conflicting operations finish, StackSets starts queued operations in request order.</p>
        <note>
        <p>
        If there are already running or queued operations, StackSets queues all incoming operations even if they
        are non-conflicting.
        </p>
        <p>
        You can't modify your stack set's execution configuration while there are running or queued operations
        for that stack set.
        </p>
        </note>
        <p>
        When <code>false</code> (default), StackSets performs one operation at a time in request order.
aws-java-sdk-cloudformation/src/main/java/com/amazonaws/services/cloudformation/model/ManagedExecution.java