Platformsh\Cli\Command\Tunnel\TunnelCommandBase::checkSupport PHP Method

    public function checkSupport()
    {
        $messages = [];
        foreach (['pcntl', 'posix'] as $extension) {
            if (!extension_loaded($extension)) {
                $messages[] = sprintf('The "%s" extension is required.', $extension);
            }
        }
        if (count($messages)) {
            throw new \RuntimeException(implode("\n", $messages));
        }
    }