def METHOD_NAME(self, *, src_challenge, dest_challenge):
    for src_phase in src_challenge.phase_set.all():
        (dest_phase, _) = Phase.objects.get_or_create(
            challenge=dest_challenge, title=src_phase.title
        )
        for attr in self.config_fields:
            setattr(dest_phase, attr, getattr(src_phase, attr))
        dest_phase.save()