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

        Calls observer ``self.observer(UpdateType.CREATED, item, index)``

def insert(self, index, x):
        """
        See :meth:`list.insert()` method

        Calls observer ``self.observer(UpdateType.CREATED, item, index)``
        """
        self.real_list.insert(index, x)
        self.observer(UpdateType.CREATED, x, index)