anchor.diff:              (nextPageNumber,boundaryPageNumber,leaves)
   
           let (startingPage,startingBoundary) = pageManager.GetRange(token)
  -        utils.SeekPage(fs, pb.PageSize, startingPage)
  +        utils.SeekPage(fs, pageSize, startingPage)
           csr.First()
           let (pageAfterLeaves, boundaryAfterLeaves, leaves) = writeLeaves startingPage startingBoundary
   
  
positive.code:                         let (nextPage,boundaryPage) = flushLeaf countPairs lastKey nextPageNumber boundaryPageNumber
                          nextPageNumber <- nextPage
                          boundaryPageNumber <- boundaryPage
                          //countPairs <- 0
                          //lastKey <- null
  
                  if pb.Position = 0 then
                      // we are here either because we just flushed a page
  
negative.code:         let token = pageManager.Begin()
  
          let putKeyWithLength (k:byte[]) =
              pb.PutByte(0uy) // flags TODO are keys ever going to have flags?
              pb.PutVarint(int64 k.Length)
              pb.PutArray(k)
  
  