### Question:
I18nManager extends AbstractService implements II18nManager { @Override public void addLabelGroup(String key, ApsProperties labels) throws ApsSystemException { try { this.getI18nDAO().addLabelGroup(key, labels); this.getCacheWrapper().addLabelGroup(key, labels); } catch (Throwable t) { logger.error("Error while adding a group of labels by key '{}'", key, t); throw new ApsSystemException("Error while adding a group of labels", t); } }  void setI18nDAO(II18nDAO i18nDao); void setLangManager(ILangManager langManager); void setCacheWrapper(II18nManagerCacheWrapper cacheWrapper); @Override void init(); @Override Map<String, ApsProperties> getLabelGroups(); @Override String renderLabel(String key, String renderingLang,
            boolean keyIfEmpty); @Override String renderLabel(String key, String renderingLang,
            boolean keyIfEmpty, Map<String, String> params); @Override String getLabel(String key, String langCode); @Override ApsProperties getLabelGroup(String key); @Override void addLabelGroup(String key, ApsProperties labels); @Override void deleteLabelGroup(String key); @Override void updateLabelGroup(String key, ApsProperties labels); @Override List<String> searchLabelsKey(String insertedText, boolean doSearchByKey,
            boolean doSearchByLang, String langCode);  }### Answer:
@Test public void testAddLabelGroup() throws Throwable { String key = "TEST_KEY"; ApsProperties labels = createLabel("prova", "test"); i18nManager.addLabelGroup(key, labels); Mockito.verify(cacheWrapper, Mockito.times(1)).addLabelGroup(key, labels); }