/**
  * {@inheritdoc}
  */
 public function getAllSources()
 {
     $sources = [];
     if ($this->isValid()) {
         $codes = $this->localeManager->getActiveCodes();
         foreach ($codes as $code) {
             $sources[] = ['id' => $code, 'text' => $code];
         }
     }
     return $sources;
 }