 
         - Returns: `true` on success, `false` otherwise.
      */
-    public func setMute(_ shouldMute: Bool, channel: UInt32, direction: Direction) -> Bool {
+    @discardableResult public func setMute(_ shouldMute: Bool, channel: UInt32, direction: Direction) -> Bool {
         if let address = validAddress(selector: kAudioDevicePropertyMute,
                                       scope: scope(direction: direction),
                                       element: channel) {


        - Returns: `true` on success, `false` otherwise.
     */
    public func setAsDefaultOutputDevice() -> Bool {
        return setDefaultDevice(kAudioHardwarePropertyDefaultOutputDevice)
    }



        - Returns: `true` on success, `false` otherwise.
     */
    @discardableResult public func setAsDefaultSystemDevice() -> Bool {
        return setDefaultDevice(kAudioHardwarePropertyDefaultSystemOutputDevice)
    }

