private Optional<Instant> instantOf(History.Event.Type type, History.Event.Type sentinelType) {
        return event(type).map(History.Event::at).filter(instant -> !hasEventAfter(sentinelType, instant));
    }
Returns true if there is a resumed event without a later suspended.
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/node/History.java