V value = localCache.get(key);
      if (value != null) {
        return value;
      }

      try {
        V newValue = valueLoader.call();
        localCache.put(key, newValue);
        return newValue;
      } catch (Exception e) {
        throw new ExecutionException(e);
      }
    }

    @Override
    public @Nullable V getIfPresent(Object key) {

        }

        newValue = computingValueReference.compute(key, function);
        if (newValue != null) {
          if (valueReference != null && newValue == valueReference.get()) {
            computingValueReference.set(newValue);
            e.setValueReference(valueReference);
            recordWrite(e, 0, now); // no change in weight
            return newValue;
          }
          try {

        V previousValue = oldValue.get();
        if (previousValue == null) {
          V newValue = loader.load(key);
          return set(newValue) ? futureValue : Futures.immediateFuture(newValue);
        }
        ListenableFuture<V> newValue = loader.reload(key, previousValue);
        if (newValue == null) {
          return Futures.immediateFuture(null);
        }