code: public void execute() throws HelloSignException {
          HttpURLConnection connection = getConnection();
          try {
              // Execute the request and save the HTTP status code
              lastHttpStatusCode = connection.getResponseCode();
  
              // Save the stream object for processing
              if (lastHttpStatusCode >= 200 && lastHttpStatusCode < 300) {
                  logger.debug("OK!");
                  lastResponseStream = connection.getInputStream();
              } else {
                  logger.error("Error! HTTP Code = " + lastHttpStatusCode);
                  lastResponseStream = connection.getErrorStream();
              }
          } catch (Exception ex) {
              throw new HelloSignException(ex);
          }
      }
docs: Executes this HTTP request and preserves the response stream and HTTP
  response code for processing.
  
  @throws HelloSignException Thrown if there is an error while making the
  HTTP request to the HelloSign API.