code: @Override
    public Map<String, Object> getBulk(String... keys) {
      return getBulk(Arrays.asList(keys), transcoder);
    }
docs: Get the values for multiple keys from the cache.
  
  @param keys the keys
  @return a map of the values (for each value that exists)
  @throws OperationTimeoutException if the global operation timeout is
  exceeded
  @throws IllegalStateException in the rare circumstance where queue is too
  full to accept any more requests