This is equivalent to invoking the corresponding x::w::panelayoutmanager method to modify the contents of the pane container. append_panes, insert_panes replace_panes, and replace_all_panes have a name value that specifies the id of a factory that generates the contents of the resulting x::w::panefactory. The position element specifies the insertion position parameter (for insert_panes) or the removal positional parameter (for remove_pane).