@Test
@SuppressWarnings("ObjectEqualsNull")
public void testEquals() {

    final SeverityComparator a = new SeverityComparator();
    final SeverityComparator b = new SeverityComparator();
    assertNotSame(a, b);
    //NPE checks.
    assertNotNull(a);
    assertFalse(a.equals(null));
    assertNotNull(b);
    assertFalse(b.equals(null));
    //Reflexive test.
    assertTrue(a.equals(a));
    assertTrue(b.equals(b));
    //Transitive test.
    assertTrue(a.equals(b));
    assertTrue(b.equals(a));
}