anchor.diff:            if prevBucketIsSet && comparer.Compare(key, prevHash) >= 0 && comparer.Compare(key, prevBucket.Last.Key) <= 0 then
               prevBucket.[key] <- value
               outerMap.Version <- outerMap.Version + 1L
  +            if cursorCounter > 0 then this.onNextEvent.Trigger(KVP(key,value))
             else
               let mutable kvp = Unchecked.defaultof<_>
               let ok = outerMap.TryFind(key, Lookup.LE, &kvp)
  
positive.code:         }
      SortedChunkedMap(outerFactory.Invoke, comparer, Some(hasher))
    new(outerFactory:Func<IComparer<'K>,IOrderedMap<'K, SortedMap<'K,'V>>>,comparer:IComparer<'K>,chunkMaxSize:int) = 
      SortedChunkedMap(outerFactory.Invoke, comparer, None, chunkMaxSize)
negative.code:         if prevBucketIsSet && comparer.Compare(key, prevHash) >= 0 && comparer.Compare(key, prevBucket.Last.Key) <= 0 then
            prevBucket.Add(key,value)
            outerMap.Version <- outerMap.Version + 1L
            if cursorCounter > 0 then this.onNextEvent.Trigger(KVP(key,value))
          else
            let mutable kvp = Unchecked.defaultof<_>
            let ok = outerMap.TryFind(key, Lookup.LE, &kvp)
  