internal void reduceBlackHole()
 {
     if (this.BlackHole != null)
     {
         CrniDupki blackHole = this.BlackHole;
         blackHole.Radius -= 2;
     }
 }
 internal void DoubleClick(Point location)
 {
     if ((this.Circles.Count >= 5) && ReferenceEquals(this.BlackHole, null))
     {
         CrniDupki redCircle = new CrniDupki(location, 50);
         if (!this.checkCollisions(redCircle))
         {
             this.BlackHole = redCircle;
         }
     }
 }