HelperManager { public boolean hasHelper(String name) { return this.helpers.get(name) != null; } HelperManager(C connector); C getConnector(); boolean hasHelper(String name); Helper<C> getHelper(String name); @SuppressWarnings("unchecked") H getHelper(String name, Class<H> cls); void filters(String name, Helper<C> helper); CollectionBuilderHelper getCollectionBuilderHelper(); void setCollectionBuilderHelper(CollectionBuilderHelper<C> helper); MapBuilderHelper getMapBuilderHelper(); void setMapBuilderHelper(MapBuilderHelper<C> helper); void setHelper(String name, Helper<C> helper);  }
@Test void hasHelper() { assertTrue(this.manager.hasHelper("test")); assertFalse(this.manager.hasHelper("no-test")); }