def METHOD_NAME(self):
    plan = SoftwarePlan(name='Test Plan')
    plan.save()
    active_version = SoftwarePlanVersion(
        role=self.old_role,
        plan=plan,
        product_rate=self.generic_product_rate,
        is_active=True
    )
    active_version.save()
    self.assertEqual(active_version.version, 1)
    change_role_for_software_plan_version('old_role', 'new_role')
    # refetch
    plan = SoftwarePlan.objects.get(name='Test Plan')
    self.assertEqual(plan.get_version().version, 1)
    self.assertEqual(plan.get_version().role.slug, 'new_role')