code: public DeleteObjectsRequest withKeys(String... keys) {
          List<KeyVersion> keyVersions = new ArrayList<KeyVersion>(keys.length);
          for (String key : keys) {
              keyVersions.add(new KeyVersion(key));
          }
          setKeys(keyVersions);
          return this;
      }
docs: Convenience method to specify a set of keys without versions.
  
  @see DeleteObjectsRequest#withKeys(List)