code: @SuppressWarnings("unchecked")
      @Collection
      public List<ExcelModuleDemoToDoItem> getToDoItems() {
          return container.allMatches(ExcelModuleDemoToDoItem.class,
                  Predicates.and(
                      ExcelModuleDemoToDoItem.Predicates.thoseOwnedBy(currentUserName()),
                      ExcelModuleDemoToDoItem.Predicates.thoseCompleted(isComplete()),
                      ExcelModuleDemoToDoItem.Predicates.thoseCategorised(getCategory(), getSubcategory())));
      }
docs: region > toDoItems (derived collection)