@Test
  public void typedMapInterfacesShouldNotBeEmpty() {
    final MapBean mapBean = enhancedRandom.nextObject(MapBean.class);

    assertThat(mapBean).isNotNull();

    assertContainsNonZeroIntegers(mapBean.getTypedMap().keySet());
    assertContainsOnlyNonEmptyPersons(mapBean.getTypedMap().values());

    assertContainsNonZeroIntegers(mapBean.getTypedSortedMap().keySet());
    assertContainsOnlyNonEmptyPersons(mapBean.getTypedSortedMap().values());

    assertContainsNonZeroIntegers(mapBean.getTypedNavigableMap().keySet());
    assertContainsOnlyNonEmptyPersons(mapBean.getTypedNavigableMap().values());

    assertContainsNonZeroIntegers(mapBean.getTypedConcurrentMap().keySet());
    assertContainsOnlyNonEmptyPersons(mapBean.getTypedConcurrentMap().values());

    assertContainsNonZeroIntegers(mapBean.getTypedConcurrentNavigableMap().keySet());
    assertContainsOnlyNonEmptyPersons(mapBean.getTypedConcurrentNavigableMap().values());
  }