@Override
 protected void onStop() {
   super.onStop();
   mFacadeManager.getReceiver(EventFacade.class).removeEventObserver(mObserver);
   mWebView.destroy();
   finish();
 }
 private String generateAPIWrapper() {
   StringBuilder wrapper = new StringBuilder();
   for (Class<? extends RpcReceiver> clazz : mFacadeManager.getRpcReceiverClasses()) {
     for (MethodDescriptor rpc : MethodDescriptor.collectFrom(clazz)) {
       wrapper.append(String.format(ANDROID_PROTOTYPE_JS, rpc.getName()));
     }
   }
   return wrapper.toString();
 }