public void finishSnapshot() {
        for (String featureName : image.finalizedVersions().keySet()) {
            if (!changes.containsKey(featureName)) {
                changes.put(featureName, Optional.empty());
            }
        }
    }
Represents changes to the cluster in the metadata image.
metadata/src/main/java/org/apache/kafka/image/FeaturesDelta.java