CobbleWall plugin

package net.itsprime;

import org.bukkit.Location;
import org.bukkit.Material;
import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;
import org.bukkit.event.Listener;
import org.bukkit.plugin.java.JavaPlugin;

/**
 * Created by Prime on 1/4/2015.
 */
public class Main extends JavaPlugin implements Listener {

    public void onEnable(){
        getConfig().options().copyDefaults(true);
        saveConfig();
    }

    public boolean onCommand(CommandSender sender, Command cmd, String label, String[] a) {
        if (!(sender instanceof Player)) {
            return false;
        }
        Player player = (Player) sender;

        if (cmd.getName().equalsIgnoreCase("cobblewall")) {
            Location loc = player.getLocation();
            for (int y = loc.getBlockY(); y > player.getWorld().getMaxHeight(); y++) {
                if (loc.getBlock().equals(Material.AIR)) {
                    loc.add(0,y,0);
                    loc.getBlock().setType(Material.COBBLESTONE);
                }
            }
            player.teleport(loc);
            return true;
        }
        return false;
    }

}