package Ġcom . music player . a ow . data . source Ċ Ċ import Ġcom . music player . a ow . data . model .* Ċ Ċ import Ġrx . Observable Ċ Ċ /** Ċ Ġ* ĠCreated Ġwith ĠAndroid ĠStudio . Ċ Ġ* ĠUser : Ċ Ġ* ĠDate : Ċ Ġ* ĠTime : Ċ Ġ* ĠDesc : ĠApp Contract Ċ Ġ*/ Ċ internal Ġinterface ĠApp Contract Ġ{ ĊĊĠĠĠ Ġ// ĠPlay ĠList ĊĊĠĠĠ Ġfun Ġplay Lists (): ĠObservable < List < Play List >> ? ĊĊĠĠĠ Ġfun Ġcached Play Lists (): ĠMutable List < Play List >? ĊĊĠĠĠ Ġfun Ġcreate ( play List : ĠPlay List ): ĠObservable < Play List > ĊĊĠĠĠ Ġfun Ġupdate ( play List : ĠPlay List ): ĠObservable < Play List > ĊĊĠĠĠ Ġfun Ġdelete ( play List : ĠPlay List ): ĠObservable < Play List > ĊĊĠĠĠ Ġ// ĠFolder ĊĊĠĠĠ Ġfun Ġfolders (): ĠObservable < Mutable List < Folder >> ĊĊĠĠĠ Ġfun Ġcreate ( folder : ĠFolder ): ĠObservable < Folder > ĊĊĠĠĠ Ġfun Ġcreate ( folders : ĠList < Folder >): ĠObservable < Mutable List < Folder >> ĊĊĠĠĠ Ġfun Ġupdate ( folder : ĠFolder ): ĠObservable < Folder > ĊĊĠĠĠ Ġfun Ġdelete ( folder : ĠFolder ): ĠObservable < Folder > ĊĊĠĠĠ Ġ// ĠSong ĊĊĠĠĠ Ġfun Ġinsert ( songs : ĠMutable List < Song >): ĠObservable < Mutable List < Song >> ĊĊĠĠĠ Ġfun Ġupdate ( song : ĠSong ): ĠObservable < Song > ĊĊĠĠĠ Ġfun Ġset Song As Favorite ( song : ĠSong , Ġfavorite : ĠBoolean ): ĠObservable < Song > Ċ Ċ } Ċ