old_contents: class Playlist(object):
      def __init__(self, playlist_uid: str, playlist_name: str, playlist_description: str = ""):
          self.playlist_uid: str = playlist_uid
          self.playlist_name: str = playlist_name
          self.playlist_description: str = playlist_description
          self.songs = []
  
new_contents: from typing import List
  
  import song_metadata
  
  
  class Playlist(object):
      def __init__(self, playlist_uid: str, playlist_name: str, playlist_description: str = ""):
          self.playlist_uid: str = playlist_uid
          self.playlist_name: str = playlist_name
          self.playlist_description: str = playlist_description
          self.songs: List[song_metadata.SongMetadata] = []
  
subject: add type hint for list ivar songs