anchor.diff:                              putKeyWithLength k
   
                   let folder st (pagenum,k:byte[]) =
  -                    let (i, sofar, firstChild, nextPageNumber, boundaryPageNumber) = st
  +                    let (i, _) = st
   
                       let neededEitherWay = 1 + Varint.SpaceNeededFor (int64 k.Length) + Varint.SpaceNeededFor (int64 pagenum)
                       let neededForInline = neededEitherWay + k.Length
  
positive.code:                         else
                              (sofar, first, nextPageNumber, boundaryPageNumber)
  
                      let addKeyToParent (sofar, firstChild, nextPageNumber, boundaryPageNumber) = 
                          if isLastChild then 
                              (sofar, firstChild, nextPageNumber, boundaryPageNumber)
                          else
  
negative.code:                     let isLastChild = (i = (children.Count - 1))
                      let couldBeRoot = (nextGeneration.Count = 0)
  
                      let maybeFlush args = 
                          let (sofar, first, nextPageNumber, boundaryPageNumber) = args
                          // TODO flush logic used to be guarded by if sofar > 0.  should it still be?
                          let available = calcAvailable sofar couldBeRoot
                          let fitsInline = (available >= neededForInline)
  