## Iterator Pattern discussion

### Ex:

Suppose you are building a music player application that allows users to create playlists and add songs to them. Implement the Iterator pattern to enable users to iterate through the songs in a playlist.

Your task is to:

$1.$ Define an interface named $**`$Iterator$`**$ with the following methods:

$-**`$hasNext$()`**$ which returns a boolean indicating whether there are more elements in the iteration.

$-**`$next$()`**$ which returns the next element in the iteration.

$2.$ Define an interface named $**`$Playlist$`**$ with the following methods:

$-**`$createIterator$()`**$ which returns an instance of the $**`$Iterator$`**$ interface that can be used to iterate over the songs in the playlist.

$-**`$addSong$($song: Song$)`**$ which adds a song to the playlist.

$3.$ Define a class named $**`$Song$`**$ that represents a single song. The $**`$Song$`**$ class should have a $**`$title$`**$ and $**`$artist$`**$ property.

$4.$ Define a class named $**`$PlaylistImpl$`**$ that implements the $**`$Playlist$`**$ interface. The $**`$PlaylistImpl$`**$ class should have an internal list of $**`$Song$`**$ objects and should implement the $**`$createIterator$()`**$ method to return an instance of an iterator that can iterate over the songs in the playlist.

$5.$ Write a sample client code that demonstrates the use of the Iterator pattern to iterate over the songs in a playlist.

Hint: You can use the built$-$in Python iterator protocol by defining the $**`\_\_$iter$\_\_()`**$ method in your $**`$PlaylistImpl$`**$ class and the $**`\_\_$next$\_\_()`**$ method in your $**`$Iterator$`**$ class.