Content update for NetEntities (#18935)

Content.Shared/Follower/FollowerSystem.cs

@@ -8,12 +8,14 @@ using Content.Shared.Physics.Pull;
 using Content.Shared.Tag;
 using Content.Shared.Verbs;
 using Robust.Shared.Containers;
+using Robust.Shared.GameStates;
 using Robust.Shared.Map;
 using Robust.Shared.Map.Events;
 using Robust.Shared.Network;
 using Robust.Shared.Utility;
 using Robust.Shared.Physics;
 using Robust.Shared.Physics.Systems;
+using Robust.Shared.Serialization;
 
 namespace Content.Shared.Follower;
 
@@ -36,6 +38,25 @@ public sealed class FollowerSystem : EntitySystem
         SubscribeLocalEvent<FollowerComponent, GotEquippedHandEvent>(OnGotEquippedHand);
         SubscribeLocalEvent<FollowedComponent, EntityTerminatingEvent>(OnFollowedTerminating);
         SubscribeLocalEvent<BeforeSaveEvent>(OnBeforeSave);
+
+        SubscribeLocalEvent<FollowedComponent, ComponentGetState>(OnFollowedGetState);
+        SubscribeLocalEvent<FollowedComponent, ComponentHandleState>(OnFollowedHandleState);
+    }
+
+    private void OnFollowedGetState(EntityUid uid, FollowedComponent component, ref ComponentGetState args)
+    {
+        args.State = new FollowedComponentState()
+        {
+            Following = GetNetEntitySet(component.Following),
+        };
+    }
+
+    private void OnFollowedHandleState(EntityUid uid, FollowedComponent component, ref ComponentHandleState args)
+    {
+        if (args.Current is not FollowedComponentState state)
+            return;
+
+        component.Following = EnsureEntitySet<FollowedComponent>(state.Following, uid);
     }
 
     private void OnBeforeSave(BeforeSaveEvent ev)
@@ -58,7 +79,7 @@ public sealed class FollowerSystem : EntitySystem
 
     private void OnGetAlternativeVerbs(GetVerbsEvent<AlternativeVerb> ev)
     {
-        if (ev.User == ev.Target || ev.Target.IsClientSide())
+        if (ev.User == ev.Target || IsClientSide(ev.Target))
             return;
 
         if (HasComp<GhostComponent>(ev.User))
@@ -221,6 +242,12 @@ public sealed class FollowerSystem : EntitySystem
             StopFollowingEntity(player, uid, followed);
         }
     }
+
+    [Serializable, NetSerializable]
+    private sealed class FollowedComponentState : ComponentState
+    {
+        public HashSet<NetEntity> Following = new();
+    }
 }
 
 public abstract class FollowEvent : EntityEventArgs