anchor.diff:  
     int toInt() => numerator ~/ denominator;
   
  +  @override
     String toString() => '$numerator/$denominator';
   
   }
positive.code:     return new Fraction._(-numerator, denominator);
    }
  
    bool operator == (other) {
      return other is Fraction
          && numerator == other.numerator
          && denominator == other.denominator;
    }
  
    int get hashCode {
      return numerator.hashCode + denominator.hashCode;
    }
  
    int compareTo(Fraction other) {
      return (numerator * other.denominator)
          .compareTo(other.numerator * denominator);
  
negative.code:  */
  library fraction;
  
  import 'package:meta/meta.dart';
  import 'int_math.dart' as int_math;
  
  /**
  