protected function createPipeline($namespace, $name, Configuration $config)
 {
     $pipeline = new Pipeline($namespace, $name, new MediaType($config->getString('type')));
     $processor = new CssUrlProcessor(['css']);
     $processor->setResourcePublisher($this->publisher);
     $pipeline->addProcessor($processor);
     if ($config->has('encoding')) {
         $pipeline->setEncoding($config->getString('encoding'));
     }
     if ($config->has('ttl')) {
         $pipeline->setTtl($config->getInteger('ttl'));
     }
     return $this->populateSources($pipeline, $config->getConfig('sources'));
 }