code: public HttpHelper getHttpHelper(Object connection) throws ActivityException {
          String user = getAttributeValueSmart(PROP_USER);
          String pass = getAttributeValueSmart(PROP_PASS);
          HttpHelper helper = new HttpHelper((HttpConnection)connection);
          if (user != null) {
              helper.getConnection().setUser(user);
              helper.getConnection().setPassword(pass);
          }
          return helper;
      }
docs: <p>
  Allows the overriding of this method without overriding invoke()
  </p>
  @return an HttpHelper instance
  @throws PropertyException