code: @Override
    public OperationFuture<CASValue<Object>> asyncGetAndTouch(final String key,
        final int exp) {
      return asyncGetAndTouch(key, exp, transcoder);
    }
docs: Get the given key to reset its expiration time.
  
  @param key the key to fetch
  @param exp the new expiration to set for the given key
  @return a future that will hold the return value of the fetch
  @throws IllegalStateException in the rare circumstance where queue is too
  full to accept any more requests