def __missing__(self, key):
        if self.default_factory is None:
            raise KeyError(key)
        else:
            ret = self[key] = self.default_factory(name=key)
            return ret
def on_select_row(self, treeview=None):
        """When a row is selected, displays the corresponding editing panel

        @var treeview: not used
        """
        self.dialog.on_backend_selected(self.get_selected_backend_id())