anchor.diff:          | (false, _) ->
   
               // new component; use a pre-allocated component
  -            if preDeque.Count > 0 then
  -                let index = Seq.head preDeque
  -                let _ : bool = preDeque.Remove index
  +            if preList.Count > 0 then
  +                let index = Seq.head preList
  +                let _ : bool = preList.Remove index
                   correlations.Add (entityId, index)
                   correlationsBack.Add (index, entityId)
                   components.Array.[index] <- comp
  
positive.code: 
      member this.Components with get () = components
      member this.FreeIndex with get () = freeIndex and internal set value = freeIndex <- value
      member internal this.FreeList with get () = freeList
      member internal this.PreDeque with get () = preDeque
      member internal this.Correlations with get () = correlations
      member internal this.CorrelationsBack with get () = correlationsBack
  
  
negative.code:                         components.Array.[index] <- comp
                          correlations.Add (entityId, index)
                          correlationsBack.Add (index, entityId)
                      else preList.Add index |> ignore
  
                  // fin
                  entityId
  