private String getFragmentTag(int viewPagerId, int fragmentPosition) {
        return "android:switcher:" + viewPagerId + ":" + fragmentPosition;
    }
This method is used to get a reference to created fragments in the adapter.

@param fragmentPosition
position of the fragment in the pager.

@return corresponding fragment that is created
during {@link #instantiateItem(ViewGroup, int)}
app/src/main/java/com/github/pockethub/android/ui/base/FragmentPagerAdapter.java