Android : AsyncTask source code questions

I was reading AsyncTask.java and there are few places that I can't understand.

1. 
   

   What does this code actually do? Judging by the comment it should create the handler, but I can't get how it can do this. The method getLooper() in the Handler class just returns the handler, so there is no way I can see it can initialize a new handler.

   
   

   
   /** @hide Used to force static handler to be created. */
   public static void init() {
       sHandler.getLooper();
   }
   
   



2. 
   

   Why putting postResultIfNotInvoked() in the overriden done() method? How can it be not invoked? If I understand this right, first the call() method of mWorker will be called and then mTaskInvoked is guaranteed to be true.

   
   

   
   mWorker = new WorkerRunnable<Params, Result>() {
       public Result call() throws Exception {
           mTaskInvoked.set(true);
           //...
           return postResult(doInBackground(mParams));
       }
   };
   
   mFuture = new FutureTask<Result>(mWorker) {
       @Override
       protected void done() {
           try {
               postResultIfNotInvoked(get());
           } catch (InterruptedException e) {
               android.util.Log.w(LOG_TAG, e);
           } catch (ExecutionException e) {
               throw new RuntimeException("An error occured while executing doInBackground()",
                       e.getCause());
           } catch (CancellationException e) {
               postResultIfNotInvoked(null);
           }
       }
   };