Stuck on "Moving work from the main thread to an asynctask" objective 1

package com.example;

import android.os.Bundle;
import android.view.View;
import java.io.IOException;
import java.net.MalformedURLException;
import android.util.Log;
import android.os.AsyncTask;

public class MainListActivity extends ListActivity {

    public static final String URL = "http://www.teamtreehouse.com";
    public static final String TAG = MainListActivity.class.getSimpleName();

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main_list);

      private class CustomAsyncTask extends AsyncTask<Object, Void, String>{

 }
        try {
            URL treehouseUrl = new URL(URL);
            HttpURLConnection connection = (HttpURLConnection) treehouseUrl.openConnection();
            connection.connect();
            int responseCode = connection.getResponseCode();
        }
        catch (MalformedURLException e) {
            Log.e(TAG, "MalformedURLException caught!", e);
        }
        catch (IOException e) {
            Log.e(TAG, "IOException caught!", e);
        }
    }
}