- public int connect_playback(string dev, BufferAttr? a = null, Flags flags = 0, CVolume? volume = null, Stream? sync_stream = null);
- public int connect_record(string dev, BufferAttr? a = null, Flags flags = 0);
+ public int connect_playback(string? dev = null, BufferAttr? a = null, Flags flags = 0, CVolume? volume = null, Stream? sync_stream = null);
+ public int connect_record(string? dev = null, BufferAttr? a = null, Flags flags = 0);