Prepares a given :class:`CTENode` `node` for deletion, by executing
            the :const:`DELETE_METHOD_GRANDMOTHER` semantics. Descendant nodes,
            if present, will be moved; in this case the optional `position` can
            be a ``callable`` which is invoked prior to each move operation (see
            :meth:`move` for details).

            By default, after each move operation, sub-tree nodes which were
            moved will be saved through a call to :meth:`Model.save` unless
            `save` is ``False``.

            This method delegates move operations to :meth:`move`.

            :param node: the :class:`CTENode` to prepare for deletion.

            :param position: optionally, a ``callable`` to invoke prior to each
                move operation.

            :param save: flag indicating whether to save after each move
                operation, ``True`` by default.

def prepare_delete_grandmother(self, node, position=None, save=True):
        """ Prepares a given :class:`CTENode` `node` for deletion, by executing
            the :const:`DELETE_METHOD_GRANDMOTHER` semantics. Descendant nodes,
            if present, will be moved; in this case the optional `position` can
            be a ``callable`` which is invoked prior to each move operation (see
            :meth:`move` for details).

            By default, after each move operation, sub-tree nodes which were
            moved will be saved through a call to :meth:`Model.save` unless
            `save` is ``False``.

            This method delegates move operations to :meth:`move`.

            :param node: the :class:`CTENode` to prepare for deletion.

            :param position: optionally, a ``callable`` to invoke prior to each
                move operation.

            :param save: flag indicating whether to save after each move
                operation, ``True`` by default.
        """
        # Move all children to the node's parent.
        for child in node.children.all():
            child.move(node.parent, position, save)