'Return tree as a GvGen object that can be output to dot file.
@param graph: gvgen.GvGen object'

def generateGraphizGraph(self, graph):

    for child in self.children.values():
        self.makeSubdomainEdge(graph, self, child)
        child.generateGraphizGraph(graph)
    for ruleset in self.rulesets:
        rulesetGvNode = graph.newItem(os.path.basename(ruleset.filename))
        graph.propertyAppend(rulesetGvNode, 'shape', 'rectangle')
        graph.propertyAppend(rulesetGvNode, 'color', 'green')
        graph.newLink(self.gvNode, rulesetGvNode)
