public MiniYaml Save(TileSet tileSet)
{
var root = FieldSaver.SaveDifferences(this, Default);
var tileYaml = tileInfo
.Select((ti, i) => Pair.New(i.ToString(), ti))
.Where(t => t.Second != null)
.Select(t => new MiniYamlNode(t.First, t.Second.Save(tileSet)))
.ToList();
root.Nodes.Add(new MiniYamlNode("Tiles", null, tileYaml));
return root;
}