public UsbStateChangedEventArgs(UsbStateChange state, DEV_BROADCAST_VOLUME volume)
 {
     this.State = state;
     this.Volume = volume;
 }
 private void SignalDeviceChange(UsbStateChange state, DEV_BROADCAST_VOLUME volume)
 {
     if (StateChanged != null)
     {
         StateChanged(new UsbStateChangedEventArgs(state, volume));
     }
 }