def test_add_already_added(self):
        prio_set_list = event._PrioritizedSetList()
        obj = object()
        prio_set_list.add(0, obj)

        with pytest.raises(ValueError) as excinfo:
            prio_set_list.add(0, obj)
        excinfo.match(r"has already been added")

        with pytest.raises(ValueError) as excinfo:
            prio_set_list.add(1, obj)
        excinfo.match(r"has already been added")
def enable_plugin(plugin):
    plugin = get_plugin_from_all(plugin)

    if plugin.enabled:
        flash(_("Plugin %(plugin)s is already enabled.", plugin=plugin.name),
              "info")
        return redirect(url_for("management.plugins"))

    try:
        plugin.enable()
        flash(_("Plugin %(plugin)s enabled. Please restart FlaskBB now.",
                plugin=plugin.name), "success")
    except OSError:
        flash(_("It seems that FlaskBB does not have enough filesystem "
                "permissions. Try removing the 'DISABLED' file by "
                "yourself instead."), "danger")

    return redirect(url_for("management.plugins"))