public function getOptions()
 {
     return [['lang', 'l', InputOption::VALUE_OPTIONAL | InputOption::VALUE_IS_ARRAY, 'languages to work with', LaravelLang::getDefaultLangs()]];
 }
 protected function buildFileKeyMapping(ListFeed $listFeed)
 {
     $mapping = [];
     foreach ($listFeed->getEntries() as $entry) {
         $values = $entry->getValues();
         if (!isset($values['file']) || !isset($values['key'])) {
             throw new \RuntimeException('each row must have file, key columns');
         }
         $file = $values['file'];
         $key = $values['key'];
         if (!isset($mapping[$file])) {
             $mapping[$file] = [];
         }
         if (!isset($mapping[$file][$key])) {
             $mapping[$file][$key] = [];
         }
         foreach ($values as $lang => $message) {
             if (in_array($lang, LaravelLang::getDefaultLangs())) {
                 $mapping[$file][$key][$lang] = $message;
             }
         }
     }
     return $mapping;
 }