// Called only if a ball is touching with the powerUp.
// If the ball is in the list then the ball has already activated the powerUp.
// If the ball is not in the list, the powerUp will be activated and the ball added in the list.
public bool ActivatePowerUp(Ball ball)
{
if (BallsInside.Contains(ball))
{
return(false);
}
IsUsed = true;
BallsInside.Add(ball);
FilterBalls();
return(true);
}
