Displays the pop-up on the workbench and gets a completion
    notification deferred. When that fires, undisplay the pop-up and
    return the result of the notification deferred verbatim.

def _runPopUp(workbench, popUp):
    """Displays the pop-up on the workbench and gets a completion
    notification deferred. When that fires, undisplay the pop-up and
    return the result of the notification deferred verbatim.

    """
    workbench.display(popUp)

    d = popUp.notifyCompleted()
    d.addCallback(_popUpCompleted, workbench)
    return d