Constructs the Configuration storage comparer.
\Drupal\Core\Config\StorageInterface $source_storage: Storage controller object used to read configuration.
\Drupal\Core\Config\StorageInterface $target_storage: Storage controller object used to write configuration.
public function __construct(StorageInterface $source_storage, StorageInterface $target_storage) {
$this->sourceStorage = $source_storage;
$this->targetStorage = $target_storage;
$this->changelist = $this
->getEmptyChangelist();
}