CoinListActivity

public class CoinListActivity extends AppCompatActivity {

    private RecyclerView mRececlerView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_coin_list);
        mRececlerView = (RecyclerView) findViewById(R.id.recyclerview_coins);
        new FirebaseDatabaseHelper().readCoins(new FirebaseDatabaseHelper.DataStatus() {
            @Override
            public void DataIsLoaded(List<Coin> coins, List<String> keys) {
                new RecyclerView_Config().setConfig(mRececlerView, CoinListActivity.this, coins, keys);
            }

            @Override
            public void DataIsInserted() {

            }

            @Override
            public void DataIsUpdated() {

            }

            @Override
            public void DataIsDeleted() {

            }
        });

    }