DirectAdmin\LetsEncrypt\Lib\Domain::getDomain PHP Method

    public function getDomain()
    {
        return $this->domain;
    }

 /**
  * Solve a challenge
  *
  * @throws \Exception
  */
 public function solveChallenge()
 {
     if (empty($this->solvableChallenges)) {
         $this->solvableChallenges();
     }
     $domains = array_merge((array) $this->domain->getDomain(), $this->subdomains);
     foreach ($domains as $domain) {
         $challenge = $this->challenges[$domain][reset($this->solvableChallenges[$domain])];
         if ($challenge->solvable()) {
             $challenge->solve();
         } else {
             throw new \Exception('Defined unsolvable challenge for ' . $domain);
         }
     }
 }