public ScalingActivity withActivityId(String activityId) {
        setActivityId(activityId);
        return this;
    }
<p>
The unique identifier of the scaling activity.
</p>

@param activityId
       The unique identifier of the scaling activity.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-applicationautoscaling/src/main/java/com/amazonaws/services/applicationautoscaling/model/ScalingActivity.java