code: public static RequestQueue newRequestQueue(Context context, HttpStack stack) {
  		RequestQueue queue = new RequestQueue(new DiskBasedCache(new File(context.getCacheDir(), "volley")), new JacksonNetwork(stack));
  		queue.start();
  		return queue;
  	}
docs: Creates a default instance of the worker pool and calls {@link RequestQueue#start()} on it.
  
  @param context A {@link Context} to use for creating the cache dir.
  @param stack An {@link com.android.volley.toolbox.HttpStack} to use for handling network calls
  @return A started {@link RequestQueue} instance.