anchor.diff:          // Preconditions
           checkNonNull "map" map
   
  -        map.Add key value
  +        map.Add (key, value)
   
       //
       let inline remove (key : int) (map : IntMap<'T>) : IntMap<'T> =
  
positive.code: 
  //
  module internal BitOps =
      (* TODO :   Re-implement the 'highestBit' function using the Count Leading Zeros (clz) operation.
                  This should be significantly faster than our current implementation (or even Okasaki's
                  original implementation, since 'clz' can be implemented by just a few operations
  
negative.code:             else t
  
      //
      static member (*inline*) private Join (p0, t0 : PatriciaMap<'T>, p1, t1) =
          let m = branchingBit' (p0, p1)
          let p = mask (p0, m)
          if zeroBit (p0, m) then
              Br (p, m, t0, t1)
          else
              Br (p, m, t1, t0)
  
      //
      static member Insert (key, value : 'T, map) =
  