public interface SoccerBallEntity {
   
    /**
     * LobbyGames soccer ball size from config
     * @param size
     */
    public void setSize(int size);
   
    /**
     * Used for spawning and respawning.
     * The game will also respawn the ball when if an entity with a UUID in the UUID set is killed
     * @param loc
     */
    public void spawn(Location loc);
   
    public void teleport(Location loc);
   
    public void remove();
   
    public boolean isValid();

    public boolean containsUUID(UUID u);
   
    public Location getLocation();
   
    public World getWorld();
   
    /**
     * In some advanced use cases, the ball may need a manual check for when a player punches it (ex. block displays).
     * This is initialized by the Soccer game during its initialization
     * @param consumer
     */
    public void setClickConsumer(Consumer<Player> consumer);

}

public class SlimeSoccerBall implements SoccerBallEntity {
   
    private Slime slime;
    private int size = 3;
   
    public void spawn(Location loc) {
        remove();
        slime = loc.getWorld().spawn(loc, Slime.class);
        slime.setSize(size);
        slime.setAI(false);
    }

    public void teleport(Location loc) {
        slime.teleport(loc);
    }

    public void remove() {
        if (slime != null) slime.remove();
    }

    public boolean isValid() {
        return slime != null && !slime.isValid();
    }

    public boolean containsUUID(UUID u) {
        return slime.getUniqueId().equals(u);
    }

    public Location getLocation() {
        return slime.getLocation();
    }

    public World getWorld() {
        return slime.getWorld();
    }

    public void setSize(int size) {
        this.size = size;
        if (slime != null) slime.setSize(size);
    }

    public void setClickConsumer(Consumer<Player> consumer) {
        // some use cases (ex. block displays) may require a manual way to detect when the player punches the ball
    }
   
}