public void relocate (Client client) {
    int x_range = space.width - client.width;
    int y_range = space.height - client.height;

    if (x_range < 0) x_range = 0;
    if (y_range < 0) y_range = 0;
   
    client.x = x_range == 0 ? 0 : random.nextInt (x_range);
    client.y = y_range == 0 ? 0 : random.nextInt (y_range);


    // origin of space
    client.x += space.x;
    client.y += space.y;

    client.move ();
  }