def unindex_item(self, item):
        """
        Un-index an item from our name_to_item dict.
        :param item: the item to un-index
        :type item: alignak.objects.item.Item
        :return: None
        """
        name_property = getattr(self.__class__, "name_property", None)
        if name_property is None:
            return
        name = getattr(item, name_property, None)
        if name is None:
            return
        self.name_to_item.pop(name, None)