input: Write a function to create a class in Python which matches the given criteria. The class should be named Song and should have two instance variables, title and artist, and three methods, str(), eq(), and length(). The str() method should return a string representation of the song with its title and artist. The eq() method should check if two songs are equal based on their title and artist. The length() method should return the length of the title of the song.
  assert Song(title="Shape of You", artist="Ed Sheeran").__str__() == 'Title: Shape of You\nArtist: Ed Sheeran'
  assert Song(title="Shape of You", artist="Ed Sheeran").__eq__(Song(title="Shape of You", artist="Ed Sheeran")) == True
  assert Song(title="Shape of You", artist="Ed Sheeran").length() == 11
  assert Song(title="Havana", artist="Camila Cabello").length() == 5
output: class Song:
      def __init__(self, title, artist):
          self.title = title
          self.artist = artist
  
      def __str__(self):
          return f'Title: {self.title}\nArtist: {self.artist}'
  
      def __eq__(self, other):
          return self.title == other.title and self.artist == other.artist
  
      def length(self):
          return len(self.title)