MapIdField { public void remove(String mapId) { mappedObjects.remove(mapId); } MapIdField(); void put(String mapId, Object value); void remove(String mapId); Object get(String mapId); boolean containsMapId(String mapId);  }
@Test public void testRemove() { mapIdField.put("aMapId", "aMapIdValue"); mapIdField.remove("aMapId"); assertFalse(mapIdField.containsMapId("aMapId")); }