V computeIfAbsent(K key, Function<K, V> factory) {
        return wrappedMap.computeIfAbsent(identityKey(key), k -> factory.apply(k.instance));
    }
A simplified {@link ConcurrentMap} using reference-equality to compare keys (similarly to {@link java.util.IdentityHashMap})

@author bjorncs
container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/SimpleConcurrentIdentityHashMap.java