code: public byte[] getResponseBytes() {
          if (responseByteStream != null) {
              try {
                  return IOUtils.toByteArray(responseByteStream);
              }
              catch (IOException e) {
                  logger.warn("Failed to extract byte array from response body. Error: " + e.getMessage());
                  return null;
              }
          }
          return this.bodyBytes;
      }
docs: This method gets the bytes of the response body.
  If this method is called, then subsequent calls to {@link #getResponseByteStream()} or {@link #getResponseBytes()}
  will return null unless the {@link Request} was made using a <code>download()</code> method.
  
  @return the bytes of the response body. Will be null if there is no body.