code: function AddrRange(begin, end) {
    begin = _toAddr(begin);
    end = _toAddr(end);
  
    if (begin.compare(end) > 0) {
      throw new Error('begin address must be <= end address');
    }
  
    this._begin = begin;
    this._end = end;
  }
docs: Range of addresses.
  @param begin Beginning address of the range
  @param end Ending address of the range
  
  Parameters can be Addr objects or parsable address strings.