How to add a fragment to the middle of FragmentStatePagerAdapter

I want to add a Fragment to the middle of the FragmentStatePagerAdapter using PagerSlidingTabStrip. But I can only add a new Fragnent at the end of the adapter. Here is the code:

public class TabsPagerAdapter extends FragmentStatePagerAdapter {
    private ArrayList<String> TABS = new ArrayList<String>();

    public TabsPagerAdapter(FragmentManager fm) {
        super(fm);
        TABS.add("First");
        TABS.add("Second");
        TABS.add("Third");
    }


    @Override
    public Fragment getItem(int position) {
        return CardFragment.newInstance(position);
    }

    @Override
    public Parcelable saveState() {
        return super.saveState();
    }

    @Override
    public int getCount() {
        return TABS.size();
    }


    @Override
    public String getPageTitle(int position) {
        return TABS.get(position);
    }


}

      

        
        
        
      

    

Here I am adding a new snippet

adapter.TABS.add(1, "ffff");

adapter.notifyDataSetChanged();

int k = viewPager.getCurrentItem();
viewPager.setCurrentItem(k + 1);

pagerSlidingTabStrip.notifyDataSetChanged();