@Test
 public void testMultiply() {
   MyDouble a = new MyDouble(1);
   MyDouble b = new MyDouble(2);
   MyDouble c = new MyDouble(3);
   QuadraticEquation TestOneQuad = new QuadraticEquation(a, b, c);
   QuadraticEquation TestTwoQuad = new QuadraticEquation(a, b, c);
   QuadraticEquation MultiQuadNull = TestOneQuad.limitedMultiply(TestTwoQuad);
   assertEquals(null, MultiQuadNull);
   QuadraticEquation TestThreeQuad = new QuadraticEquation(c);
   QuadraticEquation MultiQuad = TestOneQuad.limitedMultiply(TestThreeQuad);
   QuadraticEquation MultiTest =
       new QuadraticEquation(a.multiply(c), b.multiply(c), c.multiply(c));
   assertTrue(MultiQuad.equals(MultiTest));
 }