t.Fatalf("Error happened when append language, got %v", err)
	}

	user.Languages = []Language{language2}
	CheckUser(t, user2, user)

	AssertAssociationCount(t, user2, "Languages", 1, "AfterReplace")

	// Delete
	if err := DB.Model(&user2).Association("Languages").Delete(&Language{}); err != nil {
		t.Fatalf("Error happened when delete language, got %v", err)
	}