@Override
    public void registerAdapterDataObserver(RecyclerView.AdapterDataObserver observer) {
        super.registerAdapterDataObserver(observer);
        if (mAdapter != null) {
            mAdapter.registerAdapterDataObserver(observer);
        }
    }
@ Override public void registerAdapterDataObserver ( RecyclerView . AdapterDataObserver observer ) { super . registerAdapterDataObserver ( observer ) ; if ( mAdapter != null ) { mAdapter . registerAdapterDataObserver ( observer ) ; } }
overwrite the registerAdapterDataObserver to correctly forward all events to the FastAdapter

@param observer