@Test
 public void testDerivative() {
   assertEquals(p.derivative().apply(2), 172, 0);
   assertTrue(p.derivative() instanceof Sum);
 }
 @Test
 public void testIntergrand() {
   System.out.println(p.intergrand().apply(2));
   assertTrue(p.intergrand().apply(2) < 43 && p.intergrand().apply(2) > 42.9);
   assertTrue(p.intergrand() instanceof Sum);
 }
 @Test
 public void testPolynomial() {
   assertEquals(p.apply(2), 96, 0);
   assertEquals(p.apply(0), 0, 0);
   assertEquals(p.apply(-1), 3, 0);
 }