See :meth:`list.remove()` method

        Calls observer ``self.observer(UpdateType.DELETED, item, index)`` where
        **index** is *item position*

def remove(self, item):
        """
        See :meth:`list.remove()` method

        Calls observer ``self.observer(UpdateType.DELETED, item, index)`` where
        **index** is *item position*
        """
        index = self.index(item)
        self.real_list.remove(item)
        self.observer(UpdateType.DELETED, item, index)