def METHOD_NAME(self, delta_time):
    # Call update on all sprites
    self.player_sprite.update()
    # Bounce off the edges
    if self.player_sprite.left < 0 or self.player_sprite.right > WIDTH:
        self.player_sprite.change_x *= -1
    if self.player_sprite.bottom < 0 or self.player_sprite.top > HEIGHT:
        self.player_sprite.change_y *= -1