if err := DB.Model(&user).Omit("Languages.*").Association("Languages").Replace(&newLang); err == nil {
		t.Errorf("should failed to insert languages due to constraint failed, error: %v", err)
	}
}

func TestMany2ManyAssociationForSlice(t *testing.T) {
	users := []User{
		*GetUser("slice-many2many-1", Config{Languages: 2}),
		*GetUser("slice-many2many-2", Config{Languages: 0}),
		*GetUser("slice-many2many-3", Config{Languages: 4}),
	}