code: protected function readFileContents($language)
      {
          $fileName = $this->getFileName($language);
          $fs = $this->env->getFileSystem();
          if (!$fs->fileExists($fileName)) {
              return array();
          }
          $content = json_decode(preg_replace('/^.*?define\((.*)\);\s*/s', '$1', $fs->getFile($fileName)), true);
          if ($language === $this->baseLang) {
              $content = $content['root'];
          }
  
          $outdateInfo = [];
          $fileName = $this->getOutdateInfoFileName($language);
          if ($fs->fileExists($fileName)) {
              $outdateInfo = json_decode($fs->getFile($fileName), true);
          }
          foreach ($content as $id => $text) {
              $outdated = isset($outdateInfo[$id]) ? $outdateInfo[$id] : true;
              $content[$id] = array('id' => $id, 'name' => $id, 'content' => $text, 'outdated' => $outdated);
          }
  
          return $content;
      }
docs: Reads the contents of a language file and returns it.
  
  @param string $language language code
  @return array