@Override
    public String toString() {
        return this.value;
    }
<p>
The type of delivery events:
</p>
<ul>
<li>
<p>
<code>OPEN</code> - Open event for emails including open trackers. Excludes opens for emails addressed to more than
one recipient.
</p>
</li>
<li>
<p>
<code>CLICK</code> - Click event for emails including wrapped links. Excludes clicks for emails addressed to more
than one recipient.
</p>
</li>
</ul>
aws-java-sdk-sesv2/src/main/java/com/amazonaws/services/simpleemailv2/model/EngagementEventType.java