anchor.diff:      member this.RegisterArchetype archetypeId archetype =
           archetypes.Add (archetypeId, archetype)
   
  -    member this.IndexArchetypeSlot (entityRef : EntityRef) =
  -        archetypeSlots.[entityRef.EntityId]
  -
       member this.ReadComponents count archetypeId stream =
           match archetypes.TryGetValue archetypeId with
           | (true, archetype) -> archetype.Read count stream
  
positive.code:         match subscriptions.TryGetValue eventName with
          | (true, callbacks) -> callbacks.Remove subscriptionId
          | (false, _) -> false
  
      member this.RegisterComponentType<'c when 'c : struct and 'c :> 'c Component> componentName =
          match componentTypes.TryGetValue componentName with
  
negative.code:                 | :? EcsCallback<obj, 's> as objCallback ->
                      let evt = { EcsEventData = eventData :> obj }
                      objCallback evt this state
                  | _ -> state)
                  state callbacks.Values
  
      member this.PublishAsync<'d, 's> eventName (eventData : 'd) =
  