Session/Storage/Handler/PdoSessionHandler.php
public function open($savePath, $sessionName)
    {
        if (null === $this->pdo) {
            $this->connect($this->dsn ?: $savePath);
        }

        return true;
    }
public function open($savePath, $sessionName)
    {
        if (null === $this->pdo) {
            $this->connect($this->dsn ?: $savePath);
        }

        return true;
    }
{@inheritdoc}