public function createFinanceToken($methodName, $operationNum)
    {
        if (empty($this->options['master_token'])) {
            throw new \LogicException('The finance token cannot be created when the master token is empty.');
        }

        if (empty($this->options['login'])) {
            throw new \LogicException('The finance token cannot be created when the login is empty.');
        }

        return hash('sha256', $this->options['master_token'] . $operationNum . $methodName . $this->options['login']);
    }