if err := DB.Omit("Languages.*").Create(&user).Error; err == nil {
		t.Fatalf("should raise error when create users without languages reference")
	}

	if err := DB.Create(&user.Languages).Error; err != nil {
		t.Fatalf("no error should happen when create languages, but got %v", err)
	}

	if err := DB.Omit("Languages.*").Create(&user).Error; err != nil {