/** @trhows PntReflectionError */
	function getDerivationNav() {
		if (!isSet($this->derivationPath)) {
			return null;
		}
		if (!isSet($this->derivationNav)) {
			$this->derivationNav = PntNavigation::getInstance($this->derivationPath, $this->ownerName);
		}
		return $this->derivationNav;
	}