public function getPDO(): PDO
    {
        if ($this->pdo == null) {
            $this->pdo = new PDO($this->getDSN(), $this->username, $this->password, $this->options);

            foreach ($this->commands as $command) {
                $this->command($command['sql'], $command['params']);
            }
        }

        return $this->pdo;
    }