code: @Override
    public BulkFuture<Map<String, Object>> asyncGetBulk(String... keys) {
      return asyncGetBulk(Arrays.asList(keys), transcoder);
    }
docs: Varargs wrapper for asynchronous bulk gets with the default transcoder.
  
  @param keys one more more keys to get
  @return the future values of those keys
  @throws IllegalStateException in the rare circumstance where queue is too
  full to accept any more requests