MealListActivity - toolbar.java

public class MealListActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
       //...//

       Toolbar myToolbar = (Toolbar) findViewById(R.id.meal_list_toolbar);
       setSupportActionBar(myToolbar);

       ActionBar ab = getSupportActionBar();
       ab.setDisplayHomeAsUpEnabled(true);
    }
}