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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 get_relation(self, relation):
 """ Get the relation instance for the given relation name. :rtype: orator.orm.relations.Relation """

        from .relations import Relation

        with Relation.no_constraints(True):
            rel = getattr(self.get_model(), relation)()

        nested = self._nested_relations(relation)

        if len(nested) > 0:
            rel.get_query().with_(nested)

        return rel