@Override
  @Test
  public void ifPresentApply() {
    Integer absentKey = this.size() + 1;

    ImmutableMap<Integer, String> classUnderTest = this.classUnderTest();
    Assert.assertNull(classUnderTest.ifPresentApply(absentKey, Functions.getPassThru()));
  }
 @Test
 public void attributeNotNullWithFunction() {
   assertRejects(Predicates.attributeNotNull(Functions.getPassThru()), (Object) null);
   assertAccepts(Predicates.attributeNotNull(Functions.getPassThru()), new Object());
 }