Fonction testMultiplies BRUGIER

public void testMultiplies() {

        Rational r1 = new Rational(20,5);
        Rational r2 = new Rational(4,2);
        Rational r3 = new Rational(9,3);

        r1.multiplies(r2);

        assertEquals("8/1",r1.toString());

        r1.multiplies(r3);

        assertEquals("24/1",r1.toString());

    }