ApplicationContext for class PlaylistSongDaoImpl. This file load all
necessary bean and file for test PlaylistSongDao.
JunitTest for PlayListSongDao,testing method for this class.
Create Entity represent SQL Table playlist_song.
Create Mapping with Entity Song and Playlist represent in this Entity
foreign key.
Create implementation interface PlayListSongDao.

Create implementation for method savePlayListSong with 
@param int song id
@param int playlist_id
Get Song from database by id and get Playlist from database by id and
set all relationship between Entity: Playlist, Song, PlaylistSong.

Create implementation for method getPlaylistSongById with
@param int playlistSong_id
Get Instance PlayListSong from database and return to user.
Intefrace PlaylistSongDao which have method 
void savePlayListSong(int song_id, int playlist_id)
PlayListSong getPlayListSongById(int playlistSong_id)
Add new Entity to annotatedClass hibernate
adrian.example.musicplayer.model.Music.playlist.PlaylistSong
Add new sql script which will be insert data into table playlist_song/
Add new relationship mapping to table
Set<PlaylistSong>playlistSong