@Override
    public Filter getFilter() {
        return adapterFilter;
    }
    private Filter adapterFilter = new Filter() {
        @Override
        protected FilterResults performFiltering(CharSequence constraint) {
            List<ProductModel> filteredList = new ArrayList<>();
            if (constraint == null || constraint.length() == 0) {
                filteredList.addAll(listFull);
            } else {
                String filterPattern = constraint.toString().toLowerCase().trim();
                for (ProductModel item : listFull) {
                    if (item.getTitle().toLowerCase().contains(filterPattern)) {
                        filteredList.add(item);
                    }
                }
            }
            FilterResults results = new FilterResults();
            results.values = filteredList;

            return results;
        }
        @Override
        protected void publishResults(CharSequence constraint, FilterResults results) {
            list.clear();
            list.addAll((List) results.values);
            notifyDataSetChanged();
        }
    };