couldnt hide the progressbar after loading image in picasso?

I was trying to integrate progress bar in ma app.but i couldn't track the call back method.the progress bar always showing.how to hide when image is loded? ``` holder.imageView = (ImageView) localView.findViewById(R.id.imageView1); holder.progressBar = (ProgressBar) localView.findViewWithTag(R.id.progressBar1); localView.setTag(holder); url = getItem(paramInt); Picasso.with(getApplicationContext()) .load(url) .placeholder(R.drawable.ic_launcher) .error(R.drawable.ic_launcher) .fit() .into(holder.imageView, new Callback() { @Override public void onSuccess() { holder.imageView.setVisibility(View.VISIBLE); holder.progressBar.setVisibility(View.INVISIBLE); } @Override public void onError() { holder.progressBar.setVisibility(View.VISIBLE); holder.imageView.setVisibility(View.INVISIBLE); } }); ```