Sandbox Ultimate
Released
a hard fork of sandbox soon will be edited more enough to be its own self.
Player/Player.Undo.cs
Partial Player class file that exposes an UndoSystem.PlayerStack via a public field named Undo, initialized by calling UndoSystem.Current.For with the player's SteamId.
Networking
public sealed partial class Player
{
/// <summary>
/// Access the undo system for this player
/// </summary>
public UndoSystem.PlayerStack Undo => UndoSystem.Current.For( SteamId );
}