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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 to_CAG_agraph(self):
 """Returns a variable-only view of the GrFN in the form of an AGraph. Returns: type: A CAG constructed via variable influence in the GrFN object. """

        CAG = self.to_CAG()
        A = nx.nx_agraph.to_agraph(CAG)
        A.graph_attr.update({"dpi": 227, "fontsize": 20, "fontname": "Menlo"})
        A.node_attr.update(
            {
                "shape": "rectangle",
                "color": "#650021",
                "style": "rounded",
                "fontname": "Gill Sans",
            }
        )
        A.edge_attr.update({"color": "#650021", "arrowsize": 0.5})
        return A