input: 
  from typing import Tuple
  
  class Song:
      def __init__(self, title: str, artist: str):
          self.title = title
          self.artist = artist
    
      def __str__(self) -> str:
          return f'Title: {self.title}\nArtist: {self.artist}'
      
      def __eq__(self, other: 'Song') -> bool:
          return self.artist == other.artist and self.title == other.title
  
      def length(self) -> int:
          return len(self.title)
  
  def song_info(song: Song) -> Tuple[str, str, int]:
      """ Given a Song object, return a tuple containing its title, artist, and the length of the song's title.
      >>> song_info(Song("The Unforgiven", "Metallica"))
      ('The Unforgiven', 'Metallica', 13)
      >>> song_info(Song("Bohemian Rhapsody", "Queen"))
      ('Bohemian Rhapsody', 'Queen', 16)
      """
  
output:     return (song.title, song.artist, song.length())