Android studio - не удается разрешить "onoptionsitemselected "

---

- Привет.
Я пытаюсь создать навигационный ящик из developer.android. Но я получаю эту ошибку "не удается разрешить "onOptionsItemSelected"".

package me.success.myapplication;

import android.app.Activity;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.NavigationView;
import android.support.design.widget.Snackbar;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.support.v7.widget.Toolbar;
import android.widget.TextView;


import java.text.DateFormat;
import java.util.Calendar;

public class MainActivity extends AppCompatActivity {


    private DrawerLayout mDrawerLayout;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mDrawerLayout = findViewById(R.id.drawer_layout);


        FloatingActionButton fab = findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Here's a Snackbar", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });

        Calendar calendar = Calendar.getInstance();
        String currentDate = DateFormat.getDateInstance(DateFormat.FULL).format(calendar.getTime());

        TextView textViewDate = findViewById(R.id.text_view_date);
        textViewDate.setText(currentDate);

        TextView nava = (TextView) findViewById(R.id.navn);
        String s = "Navn"
                + System.getProperty("line.separator")
                + "Indkøbsliste"
                + System.getProperty("line.separator");


        nava.setText(s);

        Toolbar toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        ActionBar actionbar = getSupportActionBar();
        actionbar.setDisplayHomeAsUpEnabled(true);
        actionbar.setHomeAsUpIndicator(R.drawable.drawer);



        NavigationView navigationView = findViewById(R.id.nav_view);
        navigationView.setNavigationItemSelectedListener(
                new NavigationView.OnNavigationItemSelectedListener() {
                    @Override
                    public boolean onNavigationItemSelected (MenuItem menuItem) {
                        // set item as selected to persist highlight
                        menuItem.setChecked(true);
                        // close drawer when item is tapped
                        mDrawerLayout.closeDrawers();

                        // Add code here to update the UI based on the item selected
                        // For example, swap UI fragments here

                        return true;
                    }

                    @Override
                    public boolean onOptionsItemSelected(MenuItem item) {
                        switch (item.getItemId()) {
                            case android.R.id.home:
                                mDrawerLayout.openDrawer(GravityCompat.START);
                                return true;
                        }
                        return MainActivity.super.onOptionsItemSelected(item);
                    }
                });
    }
}
);

Что я уже пробовал:

Я уже искал всю информацию, которую мог найти в интернете.

---