@Test
  public void test_forceInN() {
    f1 = Values.forceInN(500);
    f2 = Values.forceInN(500);
    f3 = Values.forceInN(1000);

    assertEquals(f1, f2);
    assertEquals(f3, f2.add(f1));
    assertEquals(f1, f3.sub(f2));
    assertEquals(f3, f2.mul(2));
    assertEquals(f1, f3.div(2));
    assertEquals(Values.powerInW(2500), f2.mul(Values.speedInMpS(5)));
    assertEquals(Values.accInMss(5), f1.div(Values.massInKg(100)));
    assertEquals(Values.massInKg(100), f1.div(Values.accInMss(5)));

    assertTrue(f1.compareTo(f2) == 0);
    assertTrue(f1.compareTo(f3) == -1);
    assertTrue(f3.compareTo(f1) == 1);

    assertTrue(f1.equals(f2));

    assertTrue(!f1.isZero());
    assertTrue("500,00".equals(f1.toString()));
    assertTrue(500.0 == f1.n());
    assertTrue(0.5 == f1.kn());
  }
 @Test
 public void test_massInG() {
   m1 = Values.massInKg(1);
   m2 = Values.massInG(1000);
   m3 = Values.massInG(500);
   m4 = Values.massInG(2500);
   m5 = Values.massInG(1500);
   m6 = Values.massInG(2000);
   assertEquals(m4, m3.mul(5));
   assertEquals(m3, m4.div(5));
   assertEquals(m5, m1.add(m3));
   assertEquals(m6, m4.sub(m3));
   assertTrue(!m6.isZero());
   assertTrue("0,50".equals(m3.toString()));
   assertEquals(m1, m2);
 }
 @Test
 public void test_massInLbs() {
   m1 = Values.massInKg(1);
   m2 = Values.massInLbs(2.20462262);
   m3 = Values.massInLbs(1102.31131);
   m4 = Values.massInLbs(5511.55655);
   m5 = Values.massInLbs(1104.51593262);
   m6 = Values.massInLbs(4409.24524);
   m7 = Values.ZERO_MASS;
   assertEquals(m4, m3.mul(5));
   assertEquals(m3.kg(), m4.div(5).kg(), 0.01);
   assertEquals(m5.kg(), m1.add(m3).kg(), 4d);
   assertEquals(m6.kg(), m4.sub(m3).kg(), 0.01);
   assertTrue(m7.isZero());
   assertTrue("500,00".equals(m3.toString()));
   assertEquals(m1, m2);
 }
 @Test
 public void test_massInT() {
   m1 = Values.massInKg(1000);
   m2 = Values.massInT(1);
   m3 = Values.massInT(0.5);
   m4 = Values.massInT(2.5);
   m5 = Values.massInT(1.5);
   m6 = Values.massInT(2);
   m7 = Values.ZERO_MASS;
   assertEquals(m4, m3.mul(5));
   assertEquals(m3, m4.div(5));
   assertEquals(m5, m1.add(m3));
   assertEquals(m6, m4.sub(m3));
   assertTrue(m7.isZero());
   assertTrue("2500,00".equals(m4.toString()));
   assertEquals(m1, m2);
 }