anchor.diff:              world <- this.RegisterCorrelated true Unchecked.defaultof<'c> Unchecked.defaultof<'c2> Unchecked.defaultof<'c3> entityId world
           world
   
  -    member this.Clear world =
  +    member this.Shrink world =
           let mutable world = world
  -        for entityId in Seq.append allocated (Seq.map (fun inv -> UInt64.MaxValue - inv) unallocated) do
  +        for entityId in Seq.map (fun inv -> UInt64.MaxValue - inv) unallocated do
               world <- this.UnregisterCorrelated entityId world |> snd'
           unallocated.Clear ()
           world
  
positive.code:         let struct (unregistered2, world) = ecs.UnregisterCorrelated<'c2> entityId world
          struct (unregistered || unregistered2, world)
  
      member this.Preallocate count world =
          let mutable world = world
          for _ in 0 .. count - 1 do
              let entityId = Gen.id64
  
negative.code:             world <- this.RegisterCorrelated true Unchecked.defaultof<'c> entityId world
          world
  
      member this.Shrink world =
          let mutable world = world
          for entityId in Seq.map (fun inv -> UInt64.MaxValue - inv) unallocated do
              world <- this.UnregisterCorrelated entityId world |> snd'
          unallocated.Clear ()
          world
  