anchor.diff:  
   const binSearchThr = 4;
   const recsize = 3; //0 - hash, 1 - key, 2 - val
  +
  +final _random = new Random();
   
   _ThrowKeyError(key) => throw new Exception('Key Error: ${key} is not defined');
   
  
positive.code:             // scan the same-hash regions
              for (var j=i; j<=bm; j+=recsize) {
                bool res = false;
                for (var k=i; k<=bo; k+=recsize) {;
                  res = res || ((mekv[j+1] == okv[k+1]) && (mekv[j+2] == okv[k+2]));
                }
                if (!res) return false;
  
negative.code: 
  
    // creates either _Leaf with given _kv, or (if _kv.length is big enough) it
    // splits the _kv to multiple _Nodes
    _Node<K, V> _polish(_Owner owner, int depth, List _kv) {
      assert(_kv.length % recsize == 0);
      // depth == -1 means we are at the bottom level; we consumed all
      // information from 'hash' and we have to extend the _Leaf no matter how
      // long it gets
      if (_kv.length < recsize * leafSize || depth == -1) {
  