anchor.diff:          expect(() => Fraction(2, 0), throwsArgumentError);
           expect(() => Fraction(2, null), throwsArgumentError);
         });
  -      test('double basic', () {
  +      test('fromDouble (basic)', () {
           expect(Fraction.fromDouble(2), Fraction(2));
           expect(Fraction.fromDouble(100), Fraction(100));
         });
  -      test('double finite', () {
  +      test('fromDouble (finite)', () {
           expect(Fraction.fromDouble(1 / 2), Fraction(1, 2));
           expect(Fraction.fromDouble(1 / 4), Fraction(1, 4));
         });
  -      test('double finite (whole)', () {
  +      test('fromDouble (finite, whole)', () {
           expect(Fraction.fromDouble(5 / 2), Fraction(5, 2));
           expect(Fraction.fromDouble(9 / 4), Fraction(9, 4));
         });
  -      test('double infinite', () {
  +      test('fromDouble (infinite)', () {
           expect(Fraction.fromDouble(1 / 3), Fraction(1, 3));
           expect(Fraction.fromDouble(1 / 7), Fraction(1, 7));
         });
  -      test('double infinite (whole)', () {
  +      test('fromDouble (infinite, whole)', () {
           expect(Fraction.fromDouble(5 / 3), Fraction(5, 3));
           expect(Fraction.fromDouble(9 / 7), Fraction(9, 7));
         });
  -      test('double negative', () {
  +      test('fromDouble (negative)', () {
           expect(Fraction.fromDouble(-1 / 3), Fraction(-1, 3));
           expect(Fraction.fromDouble(-5 / 3), Fraction(-5, 3));
         });
  -      test('double all', () {
  +      test('fromDouble (all)', () {
           for (var num = -10; num <= 10; num++) {
             for (var den = -10; den <= 10; den++) {
               if (den != 0) {
  
positive.code:         expect(Complex.tryParse('1.2e2*i'), Complex(0, 120));
          expect(Complex.tryParse('1.2e-2*I'), Complex(0, 0.012));
        });
        test('parse error', () {
          expect(Complex.tryParse(''), isNull);
          expect(Complex.tryParse('e1'), isNull);
          expect(Complex.tryParse('1ii'), isNull);
  
negative.code:           }
          }
        });
        test('fromDouble (error)', () {
          expect(() => Fraction.fromDouble(double.nan), throwsArgumentError);
          expect(() => Fraction.fromDouble(double.infinity), throwsArgumentError);
          expect(() => Fraction.fromDouble(double.negativeInfinity),
  