code: public static function getNameForId($id)
      {
          if (CT::has($id)) {
              return CT::getName($id);
          }
  
          $name = token_name($id);
  
          return 'UNKNOWN' === $name ? null : $name;
      }
docs: Get token's name.
  
  It shall be used only for getting the name of token, not for checking it against excepted value.
  
  @param int $id
  
  @return null|string token name