docs: public EXXAccountInformation getExxAccountInfo() throws IOException {
      Long nonce = System.currentTimeMillis();
      String params = "accesskey=" + this.apiKey + "&nonce=" + nonce;
      String signature = CommonUtil.HmacSHA512(params, this.secretKey);
  
      return exxAuthenticated.getAccountInfo(this.apiKey, nonce, signature);
    }