QListWidget expose no AT-SPI action for itemDoubleClicked

I create a QtGui.QListWidget() from Python, add string items with .addItem(xxx), and connect the list's itemDoubleClicked signal to an action.

Now I want to script-test my UI.  Using Accerciser I can select individual items with the "Toggle" action on items, but no action seem to be available to trigger the double-click.

I even tried (without too much hope) to call the Toggle action twice quickly, with no luck.