function makeGraph(&$graph, $tree, $parent = null, $edge_label = "") {
        $main = $graph->createVertex();
        $main->setAttribute('graphviz.label', $tree->getAttributeName());
        if($parent) {
            $edge = $parent->createEdgeTo($main);
            $edge->setAttribute('graphviz.label', $edge_label);
        }
        foreach ($tree->values as $key => $child) {
            if ($child->getIsLeaf()) {
                $first_level_child = $graph->createVertex();
                $edge = $main->createEdgeTo($first_level_child);
                $edge->setAttribute('graphviz.label', $key);
                if($child->getChild('result') == 'true') {
                    $first_level_child->setAttribute('graphviz.color', 'green');
                    $first_level_child->setAttribute('graphviz.label', $child->getAttributeName());
                } else {
                    $first_level_child->setAttribute('graphviz.color', 'red');
                    $first_level_child->setAttribute('graphviz.label', "nie ".$child->getAttributeName());
                }
            } else {
                makeGraph($graph, $child, $main, $key);
            }
        }
    }