src/Selenium/Downloader.php
public function getVersion(): ?string
    {
        if (!$this->version) {
            $this->version = self::getLatestVersion();
        }

        return $this->version;
    }
public function getVersion(): ?string
    {
        if (!$this->version) {
            $this->version = self::getLatestVersion();
        }

        return $this->version;
    }
Get version that should be downloaded; if not set, attempt to retrieve latest released version