code: private function matchesAcademicDomain($domain)
      {
          if (empty($domain['tld']) or empty($domain['sld'])) {
              return false;
          }
  
          return file_exists($this->getPath($domain));
      }
docs: Helper to determine if a file exists for an academic domain.
  
  @param  array $domain
  @return bool  true if a file exists for the domain, false otherwise.