code: @Override
    public InetSocketAddress get(final Identifier key,
                                 final Callable<InetSocketAddress> valueFetcher) throws ExecutionException {
      return cache.get(key, valueFetcher);
    }
docs: Gets an address for an identifier.
  
  @param key          an identifier
  @param valueFetcher a callable to load a value for the corresponding identifier
  @return an Internet socket address
  @throws ExecutionException