@Test
 public void testSuma() {
   Fraction f3 = this.fra.sumar(new Fraction(2, 5));
   assertEquals(9, f3.getNumerator());
   assertEquals(10, f3.getDenominator());
 }
 @Test
 public void testFraction() {
   fra = new Fraction();
   assertEquals(fra.getNumerator(), 1);
   assertEquals(fra.getDenominator(), 1);
 }
 @Test
 public void testGetDenominator() {
   assertEquals(fra.getDenominator(), 2);
 }
 @Test
 public void testFractionIntInt() {
   assertEquals(fra.getNumerator(), 1);
   assertEquals(fra.getDenominator(), 2);
 }