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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 all_group_experiments(self):
 """ Similar to group_experiments, but uses the default manager to return archived experiments as well. """

        from db.models.experiments import Experiment

        if self.is_selection:
            return Experiment.all.filter(selections=self)
        return Experiment.all.filter(experiment_group=self)