code: public function auth($password)
      {
          if ($this->getConfig()->get('requirepass') === '') {
              throw new UnexpectedValueException('ERR Client sent AUTH, but no password is set');
          }
  
          if ($this->getConfig()->get('requirepass') !== $password) {
              throw new UnexpectedValueException('ERR invalid password');
          }
  
          $business = $this->getClient()->getBusiness();
          if ($business instanceof AuthInvoker) {
              $this->getClient()->setBusiness($business->getSuccessfulInvoker());
          }
  
          return true;
      }
docs: StatusReply