t.Run("Struct", func(t *testing.T) {
		pet := Pet{
			Name: "PolymorphicHasOne",
			Toy:  Toy{Name: "Toy-PolymorphicHasOne"},
		}

		if err := DB.Create(&pet).Error; err != nil {
			t.Fatalf("errors happened when create: %v", err)
		}

		CheckPet(t, pet, pet)

		var pet2 Pet
		DB.Preload("Toy").Find(&pet2, "id = ?", pet.ID)
		CheckPet(t, pet2, pet)
	})

	t.Run("Slice", func(t *testing.T) {