private void AddPlaylist(IContainerPlaylist playlist, int index) { AssertHandle(); IntPtr playlistPtr; int newIndex; lock (Spotify.Mutex) { playlistPtr = Spotify.sp_playlistcontainer_add_new_playlist(Handle, playlist.Name); newIndex = Spotify.sp_playlistcontainer_num_playlists(Handle); } if (playlistPtr != IntPtr.Zero) { lock (Spotify.Mutex) { Spotify.sp_playlistcontainer_move_playlist(Handle, newIndex, index, false); } } }