func (tks Tracks) AddTrack(path, playlist string) (Track, error) {
uuid := utils.Uuidgen("track")
tk := &Track{Uuid: uuid, Path: path, Playlist: playlist}
tks[uuid] = tk
return *tk, nil
}
func (pls Playlists) AddPlaylist(name string) (Playlist, error) {
uuid := utils.Uuidgen("playlist")
pl := &Playlist{Uuid: uuid, Name: name, Tracks: make([]string, 0)}
pls[uuid] = pl
return *pl, nil
}