code: func NewPlaybackDevice(deviceName string, channels int, format Format, rate int, bufferParams BufferParams) (p *PlaybackDevice, err error) {
  	p = new(PlaybackDevice)
  	err = p.createDevice(deviceName, channels, format, rate, true, bufferParams)
  	if err != nil {
  		return nil, err
  	}
  	return p, nil
  }
docs: // NewPlaybackDevice creates a new PlaybackDevice object.