public function getBreadcrumb() {
		$breadcrumb = [];

		// handle not set active node
		if (!isset($this->_nodes[$this->_active_path])) {
			throw new \Exception(__METHOD__.': you did not set an active node so you cannot retrieve a breadcrumb.');
			return;
		}

		// get actual node
		$actual = $this->_nodes[$this->_active_path];
		array_unshift($breadcrumb, $actual);

		// loop to the top
		while (isset($this->_nodes[$actual['parent']])) {
			$actual =& $this->_nodes[$actual['parent']];
			array_unshift($breadcrumb, $actual);
		}

		return $breadcrumb;
	}