anchor.diff:              let cts = new System.Threading.CancellationTokenSource()
               let result = ref Unchecked.defaultof<_>
               let r = geometriesNew.GetOrAdd(n, (cts, result))
  -            Async.RunSynchronously(LoadIntoPool.runWithCompensations result effects, cancellationToken= cts.Token)
  +            try
  +                Async.RunSynchronously(LoadIntoPool.runWithCompensations result effects, cancellationToken= cts.Token)
  +            with | :? OperationCanceledException as o -> ()
               r
                       
           member x.Remove(n : LodDataNode) =
  
positive.code:                 }
  
              let removeFromPool (ig,r) = 
                  Log.line "rollback, remove from pool."; 
                  pool.Remove ig |> ignore
  
              let addToRender (ig,r) =
  
negative.code:                     return geometry,Unchecked.defaultof<_>
                  }
  
              let undoLoad (geo,ref) = () //Log.line "rollback, undo load data"
  
              let addToPool (ig,r) =
                  async {
  