@OneToMany(mappedBy = "playList", cascade = {CascadeType.ALL})
              private List<PlayListLike> playListLikes = new ArrayList<>();
  
              @Column(nullable = false)
              private int likeCount = this.playListLikes.size();
  
              public void addPlayListLike(PlayListLike playListLike) {
                  this.playListLikes.add(playListLike);
                  playListLike.setPlayList(this);
                  this.likeCount = this.playListLikes.size();
              }
  
              public void removePlayListLike(PlayListLike playListLike) {
                  this.playListLikes.remove(playListLike);
                  if(playListLike.getPlayList() != this) {
                      playListLike.setPlayList(this);
                  }
                  this.likeCount = this.playListLikes.size();
              }
  
              // --------------- playListLike Service -----------------
              public PlayListLike addLike(Long memberId, Long playListId){
                  Member member = memberService.findMember(memberId);
                  PlayList playList = playListService.findVerifiedPlayList(playListId);
          
                  PlayListLike like = new PlayListLike();
                  like.setMember(member);
                  like.setPlayList(playList);
          
                  playList.addPlayListLike(like);
                  member.addLikedPlayLists(like);
          
                  return playListLikeRepository.save(like);
              }
          
              public void cancelLike(Long memberId, Long playListId){
                  Member member = memberService.findMember(memberId);
                  PlayList playList = playListService.findVerifiedPlayList(playListId);
                  List<PlayListLike> likes = getAllLikesForMemberAndPlayList(memberId, playListId);
          
                  for (PlayListLike like : likes) {
                      if (member.getMemberId().equals(like.getMember().getMemberId())) {
                          playListLikeRepository.delete(like);
                          playList.removePlayListLike(like);
                          member.removeLikedPlayLists(like);
                      } else throw new BusinessLogicException(ExceptionCode.NO_PERMISSION_EDITING_COMMENT);
                  }
              }