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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 edges(self):
 """ Return the edge characters of this node. """

        edge_str = ctypes.create_string_buffer(MAX_CHARS)

        cgaddag.gdg_edges(self.gdg, self.node, edge_str)

        return [char for char in edge_str.value.decode("ascii")]