public function mergeSource(SourceInterface $source): void
    {
        if (array_key_exists($source->sourceId(), $this->sources)) {
            unset($this->sources[$source->sourceId()]);
        } else {
            $this->newSources[$source->sourceId()] = $source;
        }
        $this->sources[$source->sourceId()] = $source;
    }