anchor.diff:    /// Constructs a new list from a given [Iterable] of booleans.
     factory BitList.from(Iterable<bool> other) {
       var length = other.length;
  -    var buffer = new Uint32List((length + OFFSET) >> SHIFT);
  +    var buffer = new Uint32List((length + bitOffset) >> bitShift);
       if (other is BitList) {
         buffer.setAll(0, other.buffer);
       } else {
         for (var i = 0, iterator = other.iterator; i < buffer.length; i++) {
           var value = 0;
  -        for (var j = 0; j <= OFFSET && iterator.moveNext(); j++) {
  +        for (var j = 0; j <= bitOffset && iterator.moveNext(); j++) {
             if (iterator.current) {
  -            value |= SET_MASK[j];
  +            value |= bitSetMask[j];
             }
           }
           buffer[i] = value;
  
positive.code:       }
      } else {
        var last = buffer.length - shift - 1;
        var otherOffset = 1 + OFFSET - offset;
        for (var i = 0; i < last; i++) {
          result.buffer[i] = ((buffer[i + shift] >> offset) & MASK) |
              ((buffer[i + shift + 1] << otherOffset) & MASK);
        }
        if (0 <= last) {
          result.buffer[last] = (buffer[buffer.length - 1] >> offset) & MASK;
        }
      }
      return result;
  
negative.code:   @override
    bool operator [](int index) {
      RangeError.checkValidIndex(index, this);
      return (buffer[index >> bitShift] & bitSetMask[index & bitOffset]) != 0;
    }
  
    /// Sets the [value] of the bit with the given [index].
  