Creating a new instance with the same variable reference

Sorry, "game" it´s to be a global (class scope) variable, now I´ve fixed

private function initGame():void{

game = new Game()

}

private function endGame():void{

removeChild(game)

//here, should I set game to null?

}

then, to start a new game:

initGame()

I just want to know if the first instance of Game will be eligible for garbage collection after calling initGame again.

If there´s need to set "game" to null in endGame function, so when I create a new instance of Game the previous instance will be eligible to garbage collection.

I think, there´s no need to set to null, once, "game" variable will be reference to the new instance, and, then, the first instance of Game created will have no more references (because "game" is the only variable reference to the instance), and then, becomes eligible for garbage collection.

I also think, that, there would be no need to nullify game in endGame,  and, in any case, once, game is a global reference of a Game instance, and being that, the game variable will always be needed in the game´s file.

Well, thinking better, maybe it´s not even a good way to restart a game making a new instance of Game.

Maybe Game class should have a restart game function.

What would be the best method?

Thanks