public void ConstructSuccess(Rational r, int n, int d)
{
Rational newR = (Rational)r.Construct(r.Numerator, r.Denominator);
Assert.True(r != newR);
Assert.Equal(r.Numerator, newR.Numerator);
Assert.Equal(r.Denominator, newR.Denominator);
}
public void ConstructFail(Rational rat, int n, int d)
{
Assert.Throws <ArgumentException>(() => rat.Construct(rat.Numerator, 0));
}