return gears.table.join( awful.key( {}, "XF86AudioRaiseVolume", function () vol:volume_up() end, { description = "Volume up", group = "System" } ), awful.key( {}, "XF86AudioLowerVolume", function () vol:volume_down() end, { description = "Volume down", group = "System" } ), awful.key( {}, "XF86AudioMute", function () vol:toggle_mute() end, { description = "Mute", group = "System" } ) )