code: def filter_items(self, items):
          '''perform filtering items by specific criteria'''
          items = self._filter_active(items)
          items = self._filter_in_nav(items)
          return itemf filter_items(self, items):
          '''perform filtering items by specific criteria'''
          items = self._filter_active(items)
          items = self._filter_in_nav(items)
          return items
docs: perform filtering items by specific criteria