/**
  * @return array
  */
 protected function getSourceLocales()
 {
     $locales = [];
     $collection = $this->localeRepository->matching(new Criteria());
     $collection->map(function (LocaleInterface $locale) use(&$locales) {
         $locales[$locale->getCode()] = $locale->getCode();
     });
     return $locales;
 }