anchor.diff:                          // these don't have a header, and they don't have a
                           // boundary ptr at the end.
   
  -                        let sofarAfterRegularPages = writeOverflowRegularPages pb fs ba numRegularPages len sofarAfterFirstPage
  +                        let sofarAfterRegularPages = writeRegularPages numRegularPages sofarAfterFirstPage
   
                           if needed > availableBeforeBoundary then
                               // assert sofar < len
  
positive.code:                             // then FLAG_ENDS_ON_BOUNDARY was set on the first
                              // overflow page in this block, since we can't set it
                              // here on this page, because this page has no header.
                              let sofarAfterBoundaryPage = buildOverflowBoundaryPage pb ba len sofarAfterRegularPages
                              let (nextPage,boundaryPage) = pageManager.GetRange(token)
                              pb.SetLastInt32(nextPage)
                              pb.Flush(fs)
                              utils.SeekPage(fs, pb.PageSize, nextPage)
                              fn sofarAfterBoundaryPage nextPage boundaryPage
                          else
                              (firstRegularPageNumber + numRegularPages, boundaryPageNumber)
  
          fn 0 startingNextPageNumber startingBoundaryPageNumber
  
      let private buildParentPage (overflows:System.Collections.Generic.Dictionary<int,int32>) (pb:PageBuilder) (children:System.Collections.Generic.List<int32 * byte[]>) stop start =
          // assert stop > start
  
negative.code: 
                          // needed gives us the number of pages, NOT including the first one
                          // which would be necessary to finish this overflow.
                          let needed = countRegularPagesNeeded (len - sofarAfterFirstPage)
  
                          // availableBeforeBoundary is the number of pages until the boundary,
                          // NOT counting the boundary page, and the first page in the block
  