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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 chk_edges(self):
 """Check that all edge nodes exist in local subset."""

        goids = set(self.go2obj)
        self.chk_edges_nodes(self.edges, goids, "is_a")
        for reltype, edges in self.edges_rel.items():
            self.chk_edges_nodes(edges, goids, reltype)