anchor.diff:      let hasEqOverlap (old:SortedChunkedMapGeneric<_,_,_>) (append:IReadOnlyOrderedMap<'K,'V>) : bool =
         if comparer.Compare(append.First.Key, old.LastUnsafe.Key) > 0 then false
         else
  -        let oldC = old.GetCursor()
  +        let oldC = new SortedChunkedMapGenericCursor<_,_,_>(old, false) :> ICursor<'K,'V>
           let appC = append.GetCursor();
           let mutable cont = true
           let mutable overlapOk = 
  
positive.code:         /////////// End read-locked code /////////////
          if doSpin then
            let nextVersion = Volatile.Read(&this.source.nextVersion)
            if version = nextVersion then doSpin <- false
            else sw.SpinOnce()
        if result then
          //if this.HasValidInner then this.innerCursor.Dispose()
  
negative.code:         /////////// End read-locked code /////////////
          if doSpin then
            let nextVersion = Volatile.Read(&this.source.nextVersion)
            if version = nextVersion || not this.synced then doSpin <- false
            else sw.SpinOnce()
        if result then
          //if this.HasValidInner then this.innerCursor.Dispose()
  