Now you are ready to add the code for the score state. The framework for that state was already done (otherwise you could not use the state in the score class). As you can see, this state only contains an update and a draw method. Nothing needs to be initialised, so an init function is superfluous.
For the draw function you can create something similar to the draw function in the Init state. It’s probably best if it resembles that one. But you can create a slightly different version depending on whether you have won or not. (You can use the method Score.hasWon() to verify that.) You also want to show the score on the screen, and ask the player if (s)he wants to play another game. For the latter you provide a text on screen, requesting to press y or n.
In the update function you check on the y and n keys. When the player presses y, then you switch back over to the GameState. If n is pressed, you exit the application.