anchor.diff:      return new $PyDict(dict);
   }
   
  -abs(n) {
  -    if (n < 0) return n * -1;
  -    else return n;
  -}
  +abs(n) => (n < 0) ? (n * -1) : n;
   
   all(iterable) {
       for (var i in iterable) {
  
positive.code:             throw new ArgumentError("step must not be 0");
      }
  
      Iterator<int> get iterator {
          return new $RangeIterator(start, stop, step);
      }
  
      int get length {
          if ((step > 0 && start > stop) || (step < 0 && start < stop))
  
negative.code:     operator /(other) {
          num result;
          other = toNum(other);
          if (other == 0)
              throw IntegerDivisionByZeroException;
          if (_value is double || other is double)
              result = _value / other;
          else
  