docs: private HttpResponse executeHead(String bucketName, String objectName, Map<String,String> headerMap)
      throws InvalidBucketNameException, NoSuchAlgorithmException, InsufficientDataException, IOException,
             InvalidKeyException, NoResponseException, XmlPullParserException, ErrorResponseException,
             InternalException {
  
      HttpResponse response = execute(Method.HEAD, getRegion(bucketName), bucketName, objectName, headerMap,
                                      null, null, 0);
      response.body().close();
      return response;
    }