anchor.diff:                          pb.SetSecondToLastInt32(firstLeaf)
                           pb.SetLastInt32(lastLeaf)
                       else
  -                        if isBoundary then
  +                        if (nextPageNumber = boundaryPageNumber) then
                               pb.SetPageFlag(FLAG_BOUNDARY_NODE)
                               let newRange = pageManager.GetRange(token)
                               nextPageNumber <- fst newRange
  
positive.code:              * already done it above.
               * 
               *)
              // TODO BUG assumption about whether this page will end up on a boundary or not?
              let available = pb.Available - (if nextPageNumber = boundaryPageNumber then sizeof<int32> else 0)
              if (available >= neededForBothInline) then
                  putArrayWithLength pb k
                  putStreamWithLength pb v vlen
  
negative.code:         buf.[cur+3] <- byte (v >>>  0)
          cur <- cur+sizeof<int32>
  
      // TODO private?
      member this.PutInt32At(at:int, ov:int) =
          // assert ov >= 0
          let v:uint32 = uint32 ov
  