public void setPrematureCrashCount(int count) {
        if (count == 0) {
            recentlyObservedUnstableDuringInit = false;
        }
        if (prematureCrashCount != count) {
            prematureCrashCount = count;
            log.log(Level.FINE, () -> "Premature crash count on " + this + " set to " + count);
        }
    }
When a node goes from an up state to a down state, update this flag with the start timestamp the node had before going down.
The cluster state broadcaster will use this to identify whether distributors have restarted.
clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/NodeInfo.java