t.Fatalf("append map 2: %v", err)
	}
	if err := DB.Model(&user).Association("Languages").Append(map[string]interface{}{"code": "am2m_map_3", "name": "AppendMap3"}); err != nil {
		t.Fatalf("append map 3: %v", err)
	}
	AssertAssociationCount(t, user, "Languages", 3, "after append 3 maps total")

	// Verify codes exist
	var langs []Language