def html_output_graph(self, node):
    graph = node['graph']
    parts = node['parts']

    graph_hash = get_graph_hash(node)
    name = "inheritance%s" % graph_hash
    path = '_images'
    dest_path = os.path.join(setup.app.builder.outdir, path)
    if not os.path.exists(dest_path):
        os.makedirs(dest_path)
    png_path = os.path.join(dest_path, name + ".png")
    path = setup.app.builder.imgpath

    # Create a mapping from fully-qualified class names to URLs.
    urls = {}
    for child in node:
        if child.get('refuri') is not None:
            urls[child['reftitle']] = child.get('refuri')
        elif child.get('refid') is not None:
            urls[child['reftitle']] = '#' + child.get('refid')

    # These arguments to dot will save a PNG file to disk and write
    # an HTML image map to stdout.
    image_map = graph.run_dot(['-Tpng', '-o%s' % png_path, '-Tcmapx'],
                              name, parts, urls)
    return ('<img src="%s/%s.png" usemap="#%s" class="inheritance"/>%s' %
            (path, name, name, image_map))
Output the graph for HTML.  This will insert a PNG with clickable
dataset/ETHPy150Open ipython/ipython-py3k/docs/sphinxext/inheritance_diagram.py/html_output_graph