IsNotNullMatcher extends AbstractUnaryMatcher { @Override protected boolean matches(Object value) { return value != null; }    }
@Test public void testSubjectIsNull() { assertThat(new IsNotNullMatcher().matches(null), is(false)); }
@Test public void testSubjectIsNotNull() { assertThat(new IsNotNullMatcher().matches(new Object()), is(true)); }