src/Viserio/Component/Mail/TransportFactory.php
protected function createSparkPostTransport(array $config): SparkPostTransport
    {
        return new SparkPostTransport(
            $this->getHttpClient($config),
            $config['secret'],
            $config['options'] ?? [],
            $config['endpoint'] ?? null
        );
    }
protected function createSparkPostTransport(array $config): SparkPostTransport
    {
        return new SparkPostTransport(
            $this->getHttpClient($config),
            $config['secret'],
            $config['options'] ?? [],
            $config['endpoint'] ?? null
        );
    }
Create an instance of the SparkPost Swift Transport driver.

@param array $config

@return \Viserio\Component\Mail\Transport\SparkPostTransport