Android : Android volley unknown constructor

I am trying to use android volley. Here is my code so far:

JsonObjectRequest getRequest = new JsonObjectRequest(Request.Method.GET, url, null,
        new Response.Listener<JSONObject>()
        {
            @Override
            public void onResponse(JSONObject response) {
                System.out.println(response);
            }
        },
        new Response.ErrorListener()
        {
            @Override
            public void onErrorResponse(VolleyError error) {
                System.out.println(error);
            }
        }
);

and here are my imports regarding volley:

import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonObjectRequest;
import com.android.volley.toolbox.Volley;

However this is giving me "Cannot resolve constructor" error. Any ideas?