anchor.diff:              | Extra (name, ty, _) ->
                   let storeType = storeTypeGeneric.MakeGenericType [|ty|]
                   let store = Activator.CreateInstance (storeType, name) :?> Store
  -                stores.Add (name, store)
  +                stores.[name] <- store
               | _ -> ()
   
       member this.Id = archetypeId
  
positive.code:             callback evt store
          boxableCallback :> obj
  
      member this.RegisterEntityInternal archetypeId comps entityRef =
          let archetype =
              match archetypes.TryGetValue archetypeId with
              | (true, archetype) -> archetype
  
negative.code: open System.Threading.Tasks
  open Prime
  
  // TODO: 3D: create try functions where applicable and do error-checking where not (search for '.[').
  
  /// Allows a value to always pass as equal with another of its same type.
  type [<CustomEquality; NoComparison; Struct>] 'a AlwaysEqual =
  