assertEquals(1, properties.size());
assertFalse(properties.keySet().isEmpty());
assertEquals(1, properties.keySet().size());
assertEquals(Collections.singleton("foo"), properties.keySet());
assertFalse(properties.values().isEmpty());
assertEquals(1, properties.values().size());
assertFalse(properties.entrySet().isEmpty());
assertEquals(1, properties.entrySet().size());
assertTrue(properties.keys().hasMoreElements());
assertEquals("foo", properties.keys().nextElement());
assertTrue(properties.propertyNames().hasMoreElements());