FluentDOM\Nodes\Compare::getPosition PHP Method

    private function getPosition(\DOMNode $node)
    {
        $hash = spl_object_hash($node);
        if (!array_key_exists($hash, $this->_cache)) {
            $this->_cache[$hash] = (int) $this->_xpath->evaluate('count(ancestor-or-self::node()/preceding::node()) + count(ancestor::node())', $node);
        }
        return $this->_cache[$hash];
    }