def METHOD_NAME(self):
    instance = ClusterableTestModel.objects.create(
        title="A test clusterable model",
        children=[
            ClusterableTestModelChild(field="A non-translatable child object"),
        ],
        translatable_children=[
            ClusterableTestModelTranslatableChild(
                field="A translatable child object"
            ),
        ],
    )
    copy = instance.copy_for_translation(locale=self.another_locale)
    instance_child = instance.children.get()
    copy_child = copy.children.get()
    instance_translatable_child = instance.translatable_children.get()
    copy_translatable_child = copy.translatable_children.get()
    self.assertNotEqual(copy, instance)
    self.assertEqual(copy.translation_key, instance.translation_key)
    self.assertEqual(copy.locale, self.another_locale)
    # Check children were copied
    self.assertNotEqual(copy_child, instance_child)
    self.assertEqual(copy_child.field, "A non-translatable child object")
    self.assertNotEqual(copy_translatable_child, instance_translatable_child)
    self.assertEqual(copy_translatable_child.field, "A translatable child object")
    # Check the translatable child's locale was updated but translation key is the same
    self.assertEqual(
        copy_translatable_child.translation_key,
        instance_translatable_child.translation_key,
    )
    self.assertEqual(copy_translatable_child.locale, self.another_locale)