anchor.diff:    _Node<K, V> _insertWith(_Owner owner, List keyValues, int kvLength,
         V combine(V x, V y), int hash, int depth) {
   
  -    int branch = (hash >> (depth * 5)) & 0x1f;
  +    int branch = (hash >> (depth * branchingBits)) & branchingMask;
       int mask = 1 << branch;
       int index = _popcount(_bitmap & (mask - 1));
   
  
positive.code:     var hash = kv[2];
      int from = 0;
      int to = into.length - recsize;
      while(from - to > binSearchThr){
        int mid = (from + to) ~/ 2;
        if (into[mid + 2] > hash){
          to = mid;
  
negative.code: 
  final _random = new Random();
  
  
  //const branching = 16;
  //const branchingBits = 4;
  //const branchingMask = 0xf;
  
  const branching = 32;
  const branchingBits = 5;
  const branchingMask = 0x1f;
  
  const leafSize = branching * 3;
  
  const binSearchThr = 16;
  const recsize = 3; //0 - key, 1 - val, 2 - hash
  
  