code: public UnfollowPlaylistRequest.Builder unfollowPlaylist(String owner_id, String playlist_id) {
      return new UnfollowPlaylistRequest.Builder(accessToken)
              .setDefaults(httpManager, scheme, host, port)
              .owner_id(owner_id)
              .playlist_id(playlist_id);
    }
docs: Remove the current user as a follower of a playlist.
  
  @param owner_id    The owners username.
  @param playlist_id The playlist's ID.
  @return An {@link UnfollowPlaylistRequest.Builder}.
  @see <a href="https://developer.spotify.com/web-api/user-guide/#spotify-uris-and-ids">Spotify: URLs &amp; IDs</a>