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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def addNode(self, node):
 """ Add a node to the graph referenced by the root """

        self.msg(4, "addNode", node)

        try:
            self.graph.restore_node(node.graphident)
        except GraphError:
            self.graph.add_node(node.graphident, node)