AssertAssociationCount(t, users, "Manager", 3, "After Append")

	if err := DB.Model(&users).Association("Manager").Append(
		GetUser("manager-slice-belongs-to-test-1", Config{}),
	).Error; err == nil {
		t.Errorf("unmatched length when update user's manager")
	}

	// Replace -> same as append

	// Delete
	if err := DB.Model(&users).Association("Company").Delete(&users[0].Company); err != nil {