docs: public AppendObjectResponse appendObject(
              String bucketName, String key, byte[] value, ObjectMetadata metadata) {
          checkNotNull(metadata, "metadata should not be null.");
          if (metadata.getContentLength() == -1) {
              metadata.setContentLength(value.length);
          }
          return this.appendObject(
                  new AppendObjectRequest(bucketName, key, RestartableInputStream.wrap(value), metadata));
      }