%%dot on Jupyter notebook doesn't work

I have installed Jupyter notebook and I downloaded the magic extension for "hierarchymagic" from this link:

https://github.com/tkf/ipython-hierarchymagic

I want to build a dot graph but I don't know why, it doesn't work:

%reload_ext hierarchymagic

%%dot

    digraph G {
        rankdir=LR;
        hello -> world;
        goodbye -> cruel -> world;
        world -> of -> warcraft;
    }

It seems that some package is missing, but I recently upgrade all packages as ipywidgets and IPython. It dosn't work anyway. Do you know how to fix the problem?