code: public static RequestQueue newRequestQueue(Context context) {
  		HttpStack stack;
  		if (Build.VERSION.SDK_INT >= 9) {
  			stack = new HurlStack();
  		} else {
  			stack = new HttpClientStack(AndroidHttpClient.newInstance("volley"));
  		}
  		return newRequestQueue(context, stack);
  	}
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.
  @return A started {@link RequestQueue} instance.