public function addPreinitDomain($domain) {
		$domain = (string) $domain;
		
		if (in_array($domain, $this->preinitDomains, true)) {
			return $this;
		}
		
		$this->preinitDomains[] = $domain;
		$this->preinitNeed      = true;
		
		return $this;
	}