protected function handleDomain(&$id) {
		if ($this->idDelimiter === null) {
			return $this->domain;
		}
		
		$delimiterPos = strpos($id, $this->idDelimiter);
		
		if ($delimiterPos === false) {
			return $this->domain;
		}
		
		$domain = substr($id, 0, $delimiterPos);
		$id     = substr($id, $delimiterPos + 1);
		
		return $domain;
	}