/** * {@inheritdoc} */ protected function init() { parent::init(); if (!$this->source->isLocal() || $this->source->getWrapper() != 'plainfile') { throw new RuntimeException('The source data must be a local file stream when uploading in parallel.'); } if (empty($this->options['concurrency'])) { throw new RuntimeException('The `concurrency` option must be specified when instantiating.'); } }